diff --git a/.dockerignore b/.dockerignore
index ffa72eaf51..4bf1492ea3 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -19,7 +19,7 @@
 !pageserver/
 !pgxn/
 !proxy/
-!object_storage/
+!endpoint_storage/
 !storage_scrubber/
 !safekeeper/
 !storage_broker/
diff --git a/.github/workflows/_build-and-test-locally.yml b/.github/workflows/_build-and-test-locally.yml
index 3a88bc844a..e31d3dec5b 100644
--- a/.github/workflows/_build-and-test-locally.yml
+++ b/.github/workflows/_build-and-test-locally.yml
@@ -275,7 +275,7 @@ jobs:
                 for io_mode in buffered direct direct-rw ; do
                   NEON_PAGESERVER_UNIT_TEST_GET_VECTORED_CONCURRENT_IO=$get_vectored_concurrent_io \
                   NEON_PAGESERVER_UNIT_TEST_VIRTUAL_FILE_IOENGINE=$io_engine \
-                  NEON_PAGESERVER_UNIT_TEST_VIRTUAL_FILE_IOMODE=$io_mode \
+                  NEON_PAGESERVER_UNIT_TEST_VIRTUAL_FILE_IO_MODE=$io_mode \
                   ${cov_prefix} \
                   cargo nextest run $CARGO_FLAGS $CARGO_FEATURES  -E 'package(pageserver)'
               done
@@ -395,7 +395,7 @@ jobs:
           BUILD_TAG: ${{ inputs.build-tag }}
           PAGESERVER_VIRTUAL_FILE_IO_ENGINE: tokio-epoll-uring
           PAGESERVER_GET_VECTORED_CONCURRENT_IO: sidecar-task
-          PAGESERVER_VIRTUAL_FILE_IO_MODE: direct
+          PAGESERVER_VIRTUAL_FILE_IO_MODE: direct-rw
           USE_LFC: ${{ matrix.lfc_state == 'with-lfc' && 'true' || 'false' }}
 
       # Temporary disable this step until we figure out why it's so flaky
diff --git a/.github/workflows/build-macos.yml b/.github/workflows/build-macos.yml
index 148c1ef5af..ecd135cc3d 100644
--- a/.github/workflows/build-macos.yml
+++ b/.github/workflows/build-macos.yml
@@ -63,13 +63,8 @@ jobs:
 
       - name: Cache postgres ${{ matrix.postgres-version }} build
         id: cache_pg
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/${{ matrix.postgres-version }}
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-pg-${{ matrix.postgres-version }}-${{ steps.pg_rev.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
 
@@ -134,25 +129,15 @@ jobs:
 
       - name: Cache postgres v17 build
         id: cache_pg
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/v17
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-pg-v17-${{ steps.pg_rev.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
 
       - name: Cache walproposer-lib
         id: cache_walproposer_lib
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/build/walproposer-lib
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-walproposer_lib-v17-${{ steps.pg_rev.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
 
@@ -218,57 +203,32 @@ jobs:
 
       - name: Cache postgres v14 build
         id: cache_pg
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/v14
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-pg-v14-${{ steps.pg_rev_v14.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
       - name: Cache postgres v15 build
         id: cache_pg_v15
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/v15
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-pg-v15-${{ steps.pg_rev_v15.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
       - name: Cache postgres v16 build
         id: cache_pg_v16
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/v16
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-pg-v16-${{ steps.pg_rev_v16.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
       - name: Cache postgres v17 build
         id: cache_pg_v17
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/v17
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-pg-v17-${{ steps.pg_rev_v17.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
 
       - name: Cache cargo deps (only for v17)
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: |
             ~/.cargo/registry
             !~/.cargo/registry/src
@@ -278,13 +238,8 @@ jobs:
 
       - name: Cache walproposer-lib
         id: cache_walproposer_lib
-        uses: tespkg/actions-cache@b7bf5fcc2f98a52ac6080eb0fd282c2f752074b1  # v1.8.0
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
-          endpoint: ${{ vars.HETZNER_CACHE_REGION }}.${{ vars.HETZNER_CACHE_ENDPOINT }}
-          bucket: ${{ vars.HETZNER_CACHE_BUCKET }}
-          accessKey: ${{ secrets.HETZNER_CACHE_ACCESS_KEY }}
-          secretKey: ${{ secrets.HETZNER_CACHE_SECRET_KEY }}
-          use-fallback: false
           path: pg_install/build/walproposer-lib
           key: v1-${{ runner.os }}-${{ runner.arch }}-${{ env.BUILD_TYPE }}-walproposer_lib-v17-${{ steps.pg_rev_v17.outputs.pg_rev }}-${{ hashFiles('Makefile') }}
 
diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
index e875cb327f..f14222bb4e 100644
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -324,7 +324,7 @@ jobs:
           TEST_RESULT_CONNSTR: "${{ secrets.REGRESS_TEST_RESULT_CONNSTR_NEW }}"
           PAGESERVER_VIRTUAL_FILE_IO_ENGINE: tokio-epoll-uring
           PAGESERVER_GET_VECTORED_CONCURRENT_IO: sidecar-task
-          PAGESERVER_VIRTUAL_FILE_IO_MODE: direct
+          PAGESERVER_VIRTUAL_FILE_IO_MODE: direct-rw
           SYNC_BETWEEN_TESTS: true
       # XXX: no coverage data handling here, since benchmarks are run on release builds,
       # while coverage is currently collected for the debug ones
@@ -1238,7 +1238,7 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.CI_ACCESS_TOKEN }}
         run: |
-          TIMEOUT=1800 # 30 minutes, usually it takes ~2-3 minutes, but if runners are busy, it might take longer
+          TIMEOUT=5400 # 90 minutes, usually it takes ~2-3 minutes, but if runners are busy, it might take longer
           INTERVAL=15 # try each N seconds
 
           last_status="" # a variable to carry the last status of the "build-and-upload-extensions" context
diff --git a/Cargo.lock b/Cargo.lock
index af5c271686..2cf260c88c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -40,7 +40,7 @@ dependencies = [
  "getrandom 0.2.11",
  "once_cell",
  "version_check",
- "zerocopy",
+ "zerocopy 0.7.31",
 ]
 
 [[package]]
@@ -1323,7 +1323,6 @@ dependencies = [
  "serde_json",
  "serde_with",
  "signal-hook",
- "spki 0.7.3",
  "tar",
  "thiserror 1.0.69",
  "tokio",
@@ -2037,6 +2036,33 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "endpoint_storage"
+version = "0.0.1"
+dependencies = [
+ "anyhow",
+ "axum",
+ "axum-extra",
+ "camino",
+ "camino-tempfile",
+ "futures",
+ "http-body-util",
+ "itertools 0.10.5",
+ "jsonwebtoken",
+ "prometheus",
+ "rand 0.8.5",
+ "remote_storage",
+ "serde",
+ "serde_json",
+ "test-log",
+ "tokio",
+ "tokio-util",
+ "tower 0.5.2",
+ "tracing",
+ "utils",
+ "workspace_hack",
+]
+
 [[package]]
 name = "enum-map"
 version = "2.5.0"
@@ -3998,33 +4024,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "object_storage"
-version = "0.0.1"
-dependencies = [
- "anyhow",
- "axum",
- "axum-extra",
- "camino",
- "camino-tempfile",
- "futures",
- "http-body-util",
- "itertools 0.10.5",
- "jsonwebtoken",
- "prometheus",
- "rand 0.8.5",
- "remote_storage",
- "serde",
- "serde_json",
- "test-log",
- "tokio",
- "tokio-util",
- "tower 0.5.2",
- "tracing",
- "utils",
- "workspace_hack",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.20.2"
@@ -4302,6 +4301,7 @@ dependencies = [
  "remote_storage",
  "reqwest",
  "rpds",
+ "rstest",
  "rustls 0.23.18",
  "scopeguard",
  "send-future",
@@ -4415,9 +4415,9 @@ dependencies = [
 
 [[package]]
 name = "papaya"
-version = "0.2.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aab21828b6b5952fdadd6c377728ffae53ec3a21b2febc47319ab65741f7e2fd"
+checksum = "6827e3fc394523c21d4464d02c0bb1c19966ea4a58a9844ad6d746214179d2bc"
 dependencies = [
  "equivalent",
  "seize",
@@ -5204,7 +5204,7 @@ dependencies = [
  "walkdir",
  "workspace_hack",
  "x509-cert",
- "zerocopy",
+ "zerocopy 0.8.24",
 ]
 
 [[package]]
@@ -5594,7 +5594,7 @@ dependencies = [
  "wasm-bindgen-futures",
  "wasm-streams",
  "web-sys",
- "webpki-roots 0.26.1",
+ "webpki-roots",
  "winreg",
 ]
 
@@ -6195,13 +6195,13 @@ checksum = "224e328af6e080cddbab3c770b1cf50f0351ba0577091ef2410c3951d835ff87"
 
 [[package]]
 name = "sentry"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "00421ed8fa0c995f07cde48ba6c89e80f2b312f74ff637326f392fbfd23abe02"
+checksum = "255914a8e53822abd946e2ce8baa41d4cded6b8e938913b7f7b9da5b7ab44335"
 dependencies = [
  "httpdate",
  "reqwest",
- "rustls 0.21.12",
+ "rustls 0.23.18",
  "sentry-backtrace",
  "sentry-contexts",
  "sentry-core",
@@ -6209,14 +6209,14 @@ dependencies = [
  "sentry-tracing",
  "tokio",
  "ureq",
- "webpki-roots 0.25.2",
+ "webpki-roots",
 ]
 
 [[package]]
 name = "sentry-backtrace"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a79194074f34b0cbe5dd33896e5928bbc6ab63a889bd9df2264af5acb186921e"
+checksum = "00293cd332a859961f24fd69258f7e92af736feaeb91020cff84dac4188a4302"
 dependencies = [
  "backtrace",
  "once_cell",
@@ -6226,9 +6226,9 @@ dependencies = [
 
 [[package]]
 name = "sentry-contexts"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eba8870c5dba2bfd9db25c75574a11429f6b95957b0a78ac02e2970dd7a5249a"
+checksum = "961990f9caa76476c481de130ada05614cd7f5aa70fb57c2142f0e09ad3fb2aa"
 dependencies = [
  "hostname",
  "libc",
@@ -6240,9 +6240,9 @@ dependencies = [
 
 [[package]]
 name = "sentry-core"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46a75011ea1c0d5c46e9e57df03ce81f5c7f0a9e199086334a1f9c0a541e0826"
+checksum = "1a6409d845707d82415c800290a5d63be5e3df3c2e417b0997c60531dfbd35ef"
 dependencies = [
  "once_cell",
  "rand 0.8.5",
@@ -6253,9 +6253,9 @@ dependencies = [
 
 [[package]]
 name = "sentry-panic"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2eaa3ecfa3c8750c78dcfd4637cfa2598b95b52897ed184b4dc77fcf7d95060d"
+checksum = "609b1a12340495ce17baeec9e08ff8ed423c337c1a84dffae36a178c783623f3"
 dependencies = [
  "sentry-backtrace",
  "sentry-core",
@@ -6263,9 +6263,9 @@ dependencies = [
 
 [[package]]
 name = "sentry-tracing"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f715932bf369a61b7256687c6f0554141b7ce097287e30e3f7ed6e9de82498fe"
+checksum = "49f4e86402d5c50239dc7d8fd3f6d5e048221d5fcb4e026d8d50ab57fe4644cb"
 dependencies = [
  "sentry-backtrace",
  "sentry-core",
@@ -6275,9 +6275,9 @@ dependencies = [
 
 [[package]]
 name = "sentry-types"
-version = "0.32.3"
+version = "0.37.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4519c900ce734f7a0eb7aba0869dfb225a7af8820634a7dd51449e3b093cfb7c"
+checksum = "3d3f117b8755dbede8260952de2aeb029e20f432e72634e8969af34324591631"
 dependencies = [
  "debugid",
  "hex",
@@ -6711,8 +6711,6 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "async-stream",
- "aws-config",
- "aws-sdk-s3",
  "camino",
  "chrono",
  "clap",
@@ -7801,7 +7799,7 @@ dependencies = [
  "rustls 0.23.18",
  "rustls-pki-types",
  "url",
- "webpki-roots 0.26.1",
+ "webpki-roots",
 ]
 
 [[package]]
@@ -8169,12 +8167,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "webpki-roots"
-version = "0.25.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14247bb57be4f377dfb94c72830b8ce8fc6beac03cf4bf7b9732eadd414123fc"
-
 [[package]]
 name = "webpki-roots"
 version = "0.26.1"
@@ -8482,6 +8474,8 @@ dependencies = [
  "regex-syntax 0.8.2",
  "reqwest",
  "rustls 0.23.18",
+ "rustls-pki-types",
+ "rustls-webpki 0.102.8",
  "scopeguard",
  "sec1 0.7.3",
  "serde",
@@ -8510,7 +8504,6 @@ dependencies = [
  "tracing-log",
  "url",
  "uuid",
- "zerocopy",
  "zeroize",
  "zstd",
  "zstd-safe",
@@ -8614,8 +8607,16 @@ version = "0.7.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c4061bedbb353041c12f413700357bec76df2c7e2ca8e4df8bac24c6bf68e3d"
 dependencies = [
- "byteorder",
- "zerocopy-derive",
+ "zerocopy-derive 0.7.31",
+]
+
+[[package]]
+name = "zerocopy"
+version = "0.8.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2586fea28e186957ef732a5f8b3be2da217d65c5969d4b1e17f973ebbe876879"
+dependencies = [
+ "zerocopy-derive 0.8.24",
 ]
 
 [[package]]
@@ -8629,6 +8630,17 @@ dependencies = [
  "syn 2.0.100",
 ]
 
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a996a8f63c5c4448cd959ac1bab0aaa3306ccfd060472f85943ee0750f0169be"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.100",
+]
+
 [[package]]
 name = "zerofrom"
 version = "0.1.5"
diff --git a/Cargo.toml b/Cargo.toml
index 9d7904a787..1c203af9e0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,7 +40,7 @@ members = [
     "libs/proxy/postgres-protocol2",
     "libs/proxy/postgres-types2",
     "libs/proxy/tokio-postgres2",
-    "object_storage",
+    "endpoint_storage",
 ]
 
 [workspace.package]
@@ -164,7 +164,7 @@ scopeguard = "1.1"
 sysinfo = "0.29.2"
 sd-notify = "0.4.1"
 send-future = "0.1.0"
-sentry = { version = "0.32", default-features = false, features = ["backtrace", "contexts", "panic", "rustls", "reqwest" ] }
+sentry = { version = "0.37", default-features = false, features = ["backtrace", "contexts", "panic", "rustls", "reqwest" ] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
 serde_path_to_error = "0.1"
@@ -220,7 +220,7 @@ uuid = { version = "1.6.1", features = ["v4", "v7", "serde"] }
 walkdir = "2.3.2"
 rustls-native-certs = "0.8"
 whoami = "1.5.1"
-zerocopy = { version = "0.7", features = ["derive"] }
+zerocopy = { version = "0.8", features = ["derive", "simd"] }
 json-structural-diff = { version = "0.2.0" }
 x509-cert = { version = "0.2.5" }
 
diff --git a/Dockerfile b/Dockerfile
index 848bfab921..3b7962dcf9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -89,7 +89,7 @@ RUN set -e \
       --bin storage_broker  \
       --bin storage_controller  \
       --bin proxy  \
-      --bin object_storage \
+      --bin endpoint_storage \
       --bin neon_local \
       --bin storage_scrubber \
       --locked --release
@@ -122,7 +122,7 @@ COPY --from=build --chown=neon:neon /home/nonroot/target/release/safekeeper
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/storage_broker      /usr/local/bin
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/storage_controller  /usr/local/bin
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/proxy               /usr/local/bin
-COPY --from=build --chown=neon:neon /home/nonroot/target/release/object_storage      /usr/local/bin
+COPY --from=build --chown=neon:neon /home/nonroot/target/release/endpoint_storage    /usr/local/bin
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/neon_local          /usr/local/bin
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/storage_scrubber    /usr/local/bin
 
diff --git a/build-tools.Dockerfile b/build-tools.Dockerfile
index 7766991a0a..f63d844afd 100644
--- a/build-tools.Dockerfile
+++ b/build-tools.Dockerfile
@@ -173,7 +173,7 @@ RUN curl -fsSL "https://github.com/protocolbuffers/protobuf/releases/download/v$
     && rm -rf protoc.zip protoc
 
 # s5cmd
-ENV S5CMD_VERSION=2.2.2
+ENV S5CMD_VERSION=2.3.0
 RUN curl -sL "https://github.com/peak/s5cmd/releases/download/v${S5CMD_VERSION}/s5cmd_${S5CMD_VERSION}_Linux-$(uname -m | sed 's/x86_64/64bit/g' | sed 's/aarch64/arm64/g').tar.gz" | tar zxvf - s5cmd \
     && chmod +x s5cmd \
     && mv s5cmd /usr/local/bin/s5cmd
@@ -206,7 +206,7 @@ RUN curl "https://awscli.amazonaws.com/awscli-exe-linux-$(uname -m).zip" -o "aws
     && rm awscliv2.zip
 
 # Mold: A Modern Linker
-ENV MOLD_VERSION=v2.34.1
+ENV MOLD_VERSION=v2.37.1
 RUN set -e \
     && git clone https://github.com/rui314/mold.git \
     && mkdir mold/build \
@@ -268,7 +268,7 @@ WORKDIR /home/nonroot
 RUN echo -e "--retry-connrefused\n--connect-timeout 15\n--retry 5\n--max-time 300\n" > /home/nonroot/.curlrc
 
 # Python
-ENV PYTHON_VERSION=3.11.10 \
+ENV PYTHON_VERSION=3.11.12 \
     PYENV_ROOT=/home/nonroot/.pyenv \
     PATH=/home/nonroot/.pyenv/shims:/home/nonroot/.pyenv/bin:/home/nonroot/.poetry/bin:$PATH
 RUN set -e \
@@ -296,12 +296,12 @@ ENV RUSTC_VERSION=1.86.0
 ENV RUSTUP_HOME="/home/nonroot/.rustup"
 ENV PATH="/home/nonroot/.cargo/bin:${PATH}"
 ARG RUSTFILT_VERSION=0.2.1
-ARG CARGO_HAKARI_VERSION=0.9.33
-ARG CARGO_DENY_VERSION=0.16.2
-ARG CARGO_HACK_VERSION=0.6.33
-ARG CARGO_NEXTEST_VERSION=0.9.85
+ARG CARGO_HAKARI_VERSION=0.9.36
+ARG CARGO_DENY_VERSION=0.18.2
+ARG CARGO_HACK_VERSION=0.6.36
+ARG CARGO_NEXTEST_VERSION=0.9.94
 ARG CARGO_CHEF_VERSION=0.1.71
-ARG CARGO_DIESEL_CLI_VERSION=2.2.6
+ARG CARGO_DIESEL_CLI_VERSION=2.2.9
 RUN curl -sSO https://static.rust-lang.org/rustup/dist/$(uname -m)-unknown-linux-gnu/rustup-init && whoami && \
 	chmod +x rustup-init && \
 	./rustup-init -y --default-toolchain ${RUSTC_VERSION} && \
diff --git a/compute_tools/Cargo.toml b/compute_tools/Cargo.toml
index d80ec41d34..8c1e7ad149 100644
--- a/compute_tools/Cargo.toml
+++ b/compute_tools/Cargo.toml
@@ -44,7 +44,6 @@ serde.workspace = true
 serde_with.workspace = true
 serde_json.workspace = true
 signal-hook.workspace = true
-spki = { version = "0.7.3", features = ["std"] }
 tar.workspace = true
 tower.workspace = true
 tower-http.workspace = true
diff --git a/compute_tools/src/bin/compute_ctl.rs b/compute_tools/src/bin/compute_ctl.rs
index aacef91d56..e337ee7b15 100644
--- a/compute_tools/src/bin/compute_ctl.rs
+++ b/compute_tools/src/bin/compute_ctl.rs
@@ -57,13 +57,24 @@ use tracing::{error, info};
 use url::Url;
 use utils::failpoint_support;
 
+// Compatibility hack: if the control plane specified any remote-ext-config
+// use the default value for extension storage proxy gateway.
+// Remove this once the control plane is updated to pass the gateway URL
+fn parse_remote_ext_config(arg: &str) -> Result<String> {
+    if arg.starts_with("http") {
+        Ok(arg.trim_end_matches('/').to_string())
+    } else {
+        Ok("http://pg-ext-s3-gateway".to_string())
+    }
+}
+
 #[derive(Parser)]
 #[command(rename_all = "kebab-case")]
 struct Cli {
     #[arg(short = 'b', long, default_value = "postgres", env = "POSTGRES_PATH")]
     pub pgbin: String,
 
-    #[arg(short = 'r', long)]
+    #[arg(short = 'r', long, value_parser = parse_remote_ext_config)]
     pub remote_ext_config: Option<String>,
 
     /// The port to bind the external listening HTTP server to. Clients running
diff --git a/compute_tools/src/metrics.rs b/compute_tools/src/metrics.rs
index fa00476fd2..e37d6120ac 100644
--- a/compute_tools/src/metrics.rs
+++ b/compute_tools/src/metrics.rs
@@ -1,8 +1,8 @@
-use metrics::core::{AtomicF64, Collector, GenericGauge};
+use metrics::core::{AtomicF64, AtomicU64, Collector, GenericCounter, GenericGauge};
 use metrics::proto::MetricFamily;
 use metrics::{
-    IntCounterVec, IntGaugeVec, UIntGaugeVec, register_gauge, register_int_counter_vec,
-    register_int_gauge_vec, register_uint_gauge_vec,
+    IntCounterVec, IntGaugeVec, UIntGaugeVec, register_gauge, register_int_counter,
+    register_int_counter_vec, register_int_gauge_vec, register_uint_gauge_vec,
 };
 use once_cell::sync::Lazy;
 
@@ -81,6 +81,22 @@ pub(crate) static COMPUTE_CTL_UP: Lazy<IntGaugeVec> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
+pub(crate) static PG_CURR_DOWNTIME_MS: Lazy<GenericGauge<AtomicF64>> = Lazy::new(|| {
+    register_gauge!(
+        "compute_pg_current_downtime_ms",
+        "Non-cumulative duration of Postgres downtime in ms; resets after successful check",
+    )
+    .expect("failed to define a metric")
+});
+
+pub(crate) static PG_TOTAL_DOWNTIME_MS: Lazy<GenericCounter<AtomicU64>> = Lazy::new(|| {
+    register_int_counter!(
+        "compute_pg_downtime_ms_total",
+        "Cumulative duration of Postgres downtime in ms",
+    )
+    .expect("failed to define a metric")
+});
+
 pub fn collect() -> Vec<MetricFamily> {
     let mut metrics = COMPUTE_CTL_UP.collect();
     metrics.extend(INSTALLED_EXTENSIONS.collect());
@@ -88,5 +104,7 @@ pub fn collect() -> Vec<MetricFamily> {
     metrics.extend(REMOTE_EXT_REQUESTS_TOTAL.collect());
     metrics.extend(DB_MIGRATION_FAILED.collect());
     metrics.extend(AUDIT_LOG_DIR_SIZE.collect());
+    metrics.extend(PG_CURR_DOWNTIME_MS.collect());
+    metrics.extend(PG_TOTAL_DOWNTIME_MS.collect());
     metrics
 }
diff --git a/compute_tools/src/monitor.rs b/compute_tools/src/monitor.rs
index 83318538cd..5a07eec833 100644
--- a/compute_tools/src/monitor.rs
+++ b/compute_tools/src/monitor.rs
@@ -6,197 +6,294 @@ use chrono::{DateTime, Utc};
 use compute_api::responses::ComputeStatus;
 use compute_api::spec::ComputeFeature;
 use postgres::{Client, NoTls};
-use tracing::{debug, error, info, warn};
+use tracing::{Level, error, info, instrument, span};
 
 use crate::compute::ComputeNode;
+use crate::metrics::{PG_CURR_DOWNTIME_MS, PG_TOTAL_DOWNTIME_MS};
 
 const MONITOR_CHECK_INTERVAL: Duration = Duration::from_millis(500);
 
-// Spin in a loop and figure out the last activity time in the Postgres.
-// Then update it in the shared state. This function never errors out.
-// NB: the only expected panic is at `Mutex` unwrap(), all other errors
-// should be handled gracefully.
-fn watch_compute_activity(compute: &ComputeNode) {
-    // Suppose that `connstr` doesn't change
-    let connstr = compute.params.connstr.clone();
-    let conf = compute.get_conn_conf(Some("compute_ctl:activity_monitor"));
+struct ComputeMonitor {
+    compute: Arc<ComputeNode>,
 
-    // During startup and configuration we connect to every Postgres database,
-    // but we don't want to count this as some user activity. So wait until
-    // the compute fully started before monitoring activity.
-    wait_for_postgres_start(compute);
+    /// The moment when Postgres had some activity,
+    /// that should prevent compute from being suspended.
+    last_active: Option<DateTime<Utc>>,
 
-    // Define `client` outside of the loop to reuse existing connection if it's active.
-    let mut client = conf.connect(NoTls);
+    /// The moment when we last tried to check Postgres.
+    last_checked: DateTime<Utc>,
+    /// The last moment we did a successful Postgres check.
+    last_up: DateTime<Utc>,
 
-    let mut sleep = false;
-    let mut prev_active_time: Option<f64> = None;
-    let mut prev_sessions: Option<i64> = None;
+    /// Only used for internal statistics change tracking
+    /// between monitor runs and can be outdated.
+    active_time: Option<f64>,
+    /// Only used for internal statistics change tracking
+    /// between monitor runs and can be outdated.
+    sessions: Option<i64>,
 
-    if compute.has_feature(ComputeFeature::ActivityMonitorExperimental) {
-        info!("starting experimental activity monitor for {}", connstr);
-    } else {
-        info!("starting activity monitor for {}", connstr);
+    /// Use experimental statistics-based activity monitor. It's no longer
+    /// 'experimental' per se, as it's enabled for everyone, but we still
+    /// keep the flag as an option to turn it off in some cases if it will
+    /// misbehave.
+    experimental: bool,
+}
+
+impl ComputeMonitor {
+    fn report_down(&self) {
+        let now = Utc::now();
+
+        // Calculate and report current downtime
+        // (since the last time Postgres was up)
+        let downtime = now.signed_duration_since(self.last_up);
+        PG_CURR_DOWNTIME_MS.set(downtime.num_milliseconds() as f64);
+
+        // Calculate and update total downtime
+        // (cumulative duration of Postgres downtime in ms)
+        let inc = now
+            .signed_duration_since(self.last_checked)
+            .num_milliseconds();
+        PG_TOTAL_DOWNTIME_MS.inc_by(inc as u64);
     }
 
-    loop {
-        // We use `continue` a lot, so it's more convenient to sleep at the top of the loop.
-        // But skip the first sleep, so we can connect to Postgres immediately.
-        if sleep {
-            // Should be outside of the mutex lock to allow others to read while we sleep.
-            thread::sleep(MONITOR_CHECK_INTERVAL);
-        } else {
-            sleep = true;
-        }
+    fn report_up(&mut self) {
+        self.last_up = Utc::now();
+        PG_CURR_DOWNTIME_MS.set(0.0);
+    }
 
-        match &mut client {
-            Ok(cli) => {
-                if cli.is_closed() {
-                    info!("connection to Postgres is closed, trying to reconnect");
+    fn downtime_info(&self) -> String {
+        format!(
+            "total_ms: {}, current_ms: {}, last_up: {}",
+            PG_TOTAL_DOWNTIME_MS.get(),
+            PG_CURR_DOWNTIME_MS.get(),
+            self.last_up
+        )
+    }
 
-                    // Connection is closed, reconnect and try again.
-                    client = conf.connect(NoTls);
-                    continue;
-                }
+    /// Spin in a loop and figure out the last activity time in the Postgres.
+    /// Then update it in the shared state. This function never errors out.
+    /// NB: the only expected panic is at `Mutex` unwrap(), all other errors
+    /// should be handled gracefully.
+    #[instrument(skip_all)]
+    pub fn run(&mut self) {
+        // Suppose that `connstr` doesn't change
+        let connstr = self.compute.params.connstr.clone();
+        let conf = self
+            .compute
+            .get_conn_conf(Some("compute_ctl:compute_monitor"));
 
-                // This is a new logic, only enable if the feature flag is set.
-                // TODO: remove this once we are sure that it works OR drop it altogether.
-                if compute.has_feature(ComputeFeature::ActivityMonitorExperimental) {
-                    // First, check if the total active time or sessions across all databases has changed.
-                    // If it did, it means that user executed some queries. In theory, it can even go down if
-                    // some databases were dropped, but it's still a user activity.
-                    match get_database_stats(cli) {
-                        Ok((active_time, sessions)) => {
-                            let mut detected_activity = false;
+        // During startup and configuration we connect to every Postgres database,
+        // but we don't want to count this as some user activity. So wait until
+        // the compute fully started before monitoring activity.
+        wait_for_postgres_start(&self.compute);
 
-                            prev_active_time = match prev_active_time {
-                                Some(prev_active_time) => {
-                                    if active_time != prev_active_time {
-                                        detected_activity = true;
-                                    }
-                                    Some(active_time)
-                                }
-                                None => Some(active_time),
-                            };
-                            prev_sessions = match prev_sessions {
-                                Some(prev_sessions) => {
-                                    if sessions != prev_sessions {
-                                        detected_activity = true;
-                                    }
-                                    Some(sessions)
-                                }
-                                None => Some(sessions),
-                            };
+        // Define `client` outside of the loop to reuse existing connection if it's active.
+        let mut client = conf.connect(NoTls);
 
-                            if detected_activity {
-                                // Update the last active time and continue, we don't need to
-                                // check backends state change.
-                                compute.update_last_active(Some(Utc::now()));
-                                continue;
-                            }
-                        }
-                        Err(e) => {
-                            error!("could not get database statistics: {}", e);
-                            continue;
-                        }
-                    }
-                }
+        info!("starting compute monitor for {}", connstr);
 
-                // Second, if database statistics is the same, check all backends state change,
-                // maybe there is some with more recent activity. `get_backends_state_change()`
-                // can return None or stale timestamp, so it's `compute.update_last_active()`
-                // responsibility to check if the new timestamp is more recent than the current one.
-                // This helps us to discover new sessions, that did nothing yet.
-                match get_backends_state_change(cli) {
-                    Ok(last_active) => {
-                        compute.update_last_active(last_active);
-                    }
-                    Err(e) => {
-                        error!("could not get backends state change: {}", e);
-                    }
-                }
-
-                // Finally, if there are existing (logical) walsenders, do not suspend.
-                //
-                // walproposer doesn't currently show up in pg_stat_replication,
-                // but protect if it will be
-                let ws_count_query = "select count(*) from pg_stat_replication where application_name != 'walproposer';";
-                match cli.query_one(ws_count_query, &[]) {
-                    Ok(r) => match r.try_get::<&str, i64>("count") {
-                        Ok(num_ws) => {
-                            if num_ws > 0 {
-                                compute.update_last_active(Some(Utc::now()));
-                                continue;
-                            }
-                        }
-                        Err(e) => {
-                            warn!("failed to parse walsenders count: {:?}", e);
-                            continue;
-                        }
-                    },
-                    Err(e) => {
-                        warn!("failed to get list of walsenders: {:?}", e);
-                        continue;
-                    }
-                }
-                //
-                // Don't suspend compute if there is an active logical replication subscription
-                //
-                // `where pid is not null` – to filter out read only computes and subscription on branches
-                //
-                let logical_subscriptions_query =
-                    "select count(*) from pg_stat_subscription where pid is not null;";
-                match cli.query_one(logical_subscriptions_query, &[]) {
-                    Ok(row) => match row.try_get::<&str, i64>("count") {
-                        Ok(num_subscribers) => {
-                            if num_subscribers > 0 {
-                                compute.update_last_active(Some(Utc::now()));
-                                continue;
-                            }
-                        }
-                        Err(e) => {
-                            warn!("failed to parse `pg_stat_subscription` count: {:?}", e);
-                            continue;
-                        }
-                    },
-                    Err(e) => {
-                        warn!(
-                            "failed to get list of active logical replication subscriptions: {:?}",
-                            e
+        loop {
+            match &mut client {
+                Ok(cli) => {
+                    if cli.is_closed() {
+                        info!(
+                            downtime_info = self.downtime_info(),
+                            "connection to Postgres is closed, trying to reconnect"
                         );
-                        continue;
-                    }
-                }
-                //
-                // Do not suspend compute if autovacuum is running
-                //
-                let autovacuum_count_query = "select count(*) from pg_stat_activity where backend_type = 'autovacuum worker'";
-                match cli.query_one(autovacuum_count_query, &[]) {
-                    Ok(r) => match r.try_get::<&str, i64>("count") {
-                        Ok(num_workers) => {
-                            if num_workers > 0 {
-                                compute.update_last_active(Some(Utc::now()));
-                                continue;
+                        self.report_down();
+
+                        // Connection is closed, reconnect and try again.
+                        client = conf.connect(NoTls);
+                    } else {
+                        match self.check(cli) {
+                            Ok(_) => {
+                                self.report_up();
+                                self.compute.update_last_active(self.last_active);
+                            }
+                            Err(e) => {
+                                // Although we have many places where we can return errors in `check()`,
+                                // normally it shouldn't happen. I.e., we will likely return error if
+                                // connection got broken, query timed out, Postgres returned invalid data, etc.
+                                // In all such cases it's suspicious, so let's report this as downtime.
+                                self.report_down();
+                                error!(
+                                    downtime_info = self.downtime_info(),
+                                    "could not check Postgres: {}", e
+                                );
+
+                                // Reconnect to Postgres just in case. During tests, I noticed
+                                // that queries in `check()` can fail with `connection closed`,
+                                // but `cli.is_closed()` above doesn't detect it. Even if old
+                                // connection is still alive, it will be dropped when we reassign
+                                // `client` to a new connection.
+                                client = conf.connect(NoTls);
                             }
                         }
-                        Err(e) => {
-                            warn!("failed to parse autovacuum workers count: {:?}", e);
-                            continue;
-                        }
-                    },
-                    Err(e) => {
-                        warn!("failed to get list of autovacuum workers: {:?}", e);
-                        continue;
                     }
                 }
-            }
-            Err(e) => {
-                debug!("could not connect to Postgres: {}, retrying", e);
+                Err(e) => {
+                    info!(
+                        downtime_info = self.downtime_info(),
+                        "could not connect to Postgres: {}, retrying", e
+                    );
+                    self.report_down();
 
-                // Establish a new connection and try again.
-                client = conf.connect(NoTls);
+                    // Establish a new connection and try again.
+                    client = conf.connect(NoTls);
+                }
+            }
+
+            // Reset the `last_checked` timestamp and sleep before the next iteration.
+            self.last_checked = Utc::now();
+            thread::sleep(MONITOR_CHECK_INTERVAL);
+        }
+    }
+
+    #[instrument(skip_all)]
+    fn check(&mut self, cli: &mut Client) -> anyhow::Result<()> {
+        // This is new logic, only enable if the feature flag is set.
+        // TODO: remove this once we are sure that it works OR drop it altogether.
+        if self.experimental {
+            // Check if the total active time or sessions across all databases has changed.
+            // If it did, it means that user executed some queries. In theory, it can even go down if
+            // some databases were dropped, but it's still user activity.
+            match get_database_stats(cli) {
+                Ok((active_time, sessions)) => {
+                    let mut detected_activity = false;
+
+                    if let Some(prev_active_time) = self.active_time {
+                        if active_time != prev_active_time {
+                            detected_activity = true;
+                        }
+                    }
+                    self.active_time = Some(active_time);
+
+                    if let Some(prev_sessions) = self.sessions {
+                        if sessions != prev_sessions {
+                            detected_activity = true;
+                        }
+                    }
+                    self.sessions = Some(sessions);
+
+                    if detected_activity {
+                        // Update the last active time and continue, we don't need to
+                        // check backends state change.
+                        self.last_active = Some(Utc::now());
+                        return Ok(());
+                    }
+                }
+                Err(e) => {
+                    return Err(anyhow::anyhow!("could not get database statistics: {}", e));
+                }
             }
         }
+
+        // If database statistics are the same, check all backends for state changes.
+        // Maybe there are some with more recent activity. `get_backends_state_change()`
+        // can return None or stale timestamp, so it's `compute.update_last_active()`
+        // responsibility to check if the new timestamp is more recent than the current one.
+        // This helps us to discover new sessions that have not done anything yet.
+        match get_backends_state_change(cli) {
+            Ok(last_active) => match (last_active, self.last_active) {
+                (Some(last_active), Some(prev_last_active)) => {
+                    if last_active > prev_last_active {
+                        self.last_active = Some(last_active);
+                        return Ok(());
+                    }
+                }
+                (Some(last_active), None) => {
+                    self.last_active = Some(last_active);
+                    return Ok(());
+                }
+                _ => {}
+            },
+            Err(e) => {
+                return Err(anyhow::anyhow!(
+                    "could not get backends state change: {}",
+                    e
+                ));
+            }
+        }
+
+        // If there are existing (logical) walsenders, do not suspend.
+        //
+        // N.B. walproposer doesn't currently show up in pg_stat_replication,
+        // but protect if it will.
+        const WS_COUNT_QUERY: &str =
+            "select count(*) from pg_stat_replication where application_name != 'walproposer';";
+        match cli.query_one(WS_COUNT_QUERY, &[]) {
+            Ok(r) => match r.try_get::<&str, i64>("count") {
+                Ok(num_ws) => {
+                    if num_ws > 0 {
+                        self.last_active = Some(Utc::now());
+                        return Ok(());
+                    }
+                }
+                Err(e) => {
+                    let err: anyhow::Error = e.into();
+                    return Err(err.context("failed to parse walsenders count"));
+                }
+            },
+            Err(e) => {
+                return Err(anyhow::anyhow!("failed to get list of walsenders: {}", e));
+            }
+        }
+
+        // Don't suspend compute if there is an active logical replication subscription
+        //
+        // `where pid is not null` – to filter out read only computes and subscription on branches
+        const LOGICAL_SUBSCRIPTIONS_QUERY: &str =
+            "select count(*) from pg_stat_subscription where pid is not null;";
+        match cli.query_one(LOGICAL_SUBSCRIPTIONS_QUERY, &[]) {
+            Ok(row) => match row.try_get::<&str, i64>("count") {
+                Ok(num_subscribers) => {
+                    if num_subscribers > 0 {
+                        self.last_active = Some(Utc::now());
+                        return Ok(());
+                    }
+                }
+                Err(e) => {
+                    return Err(anyhow::anyhow!(
+                        "failed to parse 'pg_stat_subscription' count: {}",
+                        e
+                    ));
+                }
+            },
+            Err(e) => {
+                return Err(anyhow::anyhow!(
+                    "failed to get list of active logical replication subscriptions: {}",
+                    e
+                ));
+            }
+        }
+
+        // Do not suspend compute if autovacuum is running
+        const AUTOVACUUM_COUNT_QUERY: &str =
+            "select count(*) from pg_stat_activity where backend_type = 'autovacuum worker'";
+        match cli.query_one(AUTOVACUUM_COUNT_QUERY, &[]) {
+            Ok(r) => match r.try_get::<&str, i64>("count") {
+                Ok(num_workers) => {
+                    if num_workers > 0 {
+                        self.last_active = Some(Utc::now());
+                        return Ok(());
+                    };
+                }
+                Err(e) => {
+                    return Err(anyhow::anyhow!(
+                        "failed to parse autovacuum workers count: {}",
+                        e
+                    ));
+                }
+            },
+            Err(e) => {
+                return Err(anyhow::anyhow!(
+                    "failed to get list of autovacuum workers: {}",
+                    e
+                ));
+            }
+        }
+
+        Ok(())
     }
 }
 
@@ -315,9 +412,24 @@ fn get_backends_state_change(cli: &mut Client) -> anyhow::Result<Option<DateTime
 /// Launch a separate compute monitor thread and return its `JoinHandle`.
 pub fn launch_monitor(compute: &Arc<ComputeNode>) -> thread::JoinHandle<()> {
     let compute = Arc::clone(compute);
+    let experimental = compute.has_feature(ComputeFeature::ActivityMonitorExperimental);
+    let now = Utc::now();
+    let mut monitor = ComputeMonitor {
+        compute,
+        last_active: None,
+        last_checked: now,
+        last_up: now,
+        active_time: None,
+        sessions: None,
+        experimental,
+    };
 
+    let span = span!(Level::INFO, "compute_monitor");
     thread::Builder::new()
         .name("compute-monitor".into())
-        .spawn(move || watch_compute_activity(&compute))
+        .spawn(move || {
+            let _enter = span.enter();
+            monitor.run();
+        })
         .expect("cannot launch compute monitor thread")
 }
diff --git a/compute_tools/src/tls.rs b/compute_tools/src/tls.rs
index 8f465c7300..ab32a9459a 100644
--- a/compute_tools/src/tls.rs
+++ b/compute_tools/src/tls.rs
@@ -3,7 +3,6 @@ use std::{io::Write, os::unix::fs::OpenOptionsExt, path::Path, time::Duration};
 use anyhow::{Context, Result, bail};
 use compute_api::responses::TlsConfig;
 use ring::digest;
-use spki::der::{Decode, PemReader};
 use x509_cert::Certificate;
 
 #[derive(Clone, Copy)]
@@ -52,7 +51,7 @@ pub fn update_key_path_blocking(pg_data: &Path, tls_config: &TlsConfig) {
         match try_update_key_path_blocking(pg_data, tls_config) {
             Ok(()) => break,
             Err(e) => {
-                tracing::error!("could not create key file {e:?}");
+                tracing::error!(error = ?e, "could not create key file");
                 std::thread::sleep(Duration::from_secs(1))
             }
         }
@@ -92,8 +91,14 @@ fn try_update_key_path_blocking(pg_data: &Path, tls_config: &TlsConfig) -> Resul
 fn verify_key_cert(key: &str, cert: &str) -> Result<()> {
     use x509_cert::der::oid::db::rfc5912::ECDSA_WITH_SHA_256;
 
-    let cert = Certificate::decode(&mut PemReader::new(cert.as_bytes()).context("pem reader")?)
-        .context("decode cert")?;
+    let certs = Certificate::load_pem_chain(cert.as_bytes())
+        .context("decoding PEM encoded certificates")?;
+
+    // First certificate is our server-cert,
+    // all the rest of the certs are the CA cert chain.
+    let Some(cert) = certs.first() else {
+        bail!("no certificates found");
+    };
 
     match cert.signature_algorithm.oid {
         ECDSA_WITH_SHA_256 => {
@@ -115,3 +120,82 @@ fn verify_key_cert(key: &str, cert: &str) -> Result<()> {
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::verify_key_cert;
+
+    /// Real certificate chain file, generated by cert-manager in dev.
+    /// The server auth certificate has expired since 2025-04-24T15:41:35Z.
+    const CERT: &str = "
+-----BEGIN CERTIFICATE-----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=
+-----END CERTIFICATE-----
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+";
+
+    /// The key corresponding to [`CERT`]
+    const KEY: &str = "
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIDnAnrqmIJjndCLWP1iIO5X3X63Aia48TGpGuMXwvm6IoAoGCCqGSM49
+AwEHoUQDQgAExUAnBtpvxFRwImbUrGIFZx4KE41C/ybcH3a6b89rdG1UWZgZkioZ
+aOd7j1fWOXihRgJkeeKff4E9njt8VO7wIA==
+-----END EC PRIVATE KEY-----
+";
+
+    /// An incorrect key.
+    const INCORRECT_KEY: &str = "
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIL6WqqBDyvM0HWz7Ir5M5+jhFWB7IzOClGn26OPrzHCXoAoGCCqGSM49
+AwEHoUQDQgAE7XVvdOy5lfwtNKb+gJEUtnG+DrnnXLY5LsHDeGQKV9PTRcEMeCrG
+YZzHyML4P6Sr4yi2ts+4B9i47uvAG8+XwQ==
+-----END EC PRIVATE KEY-----
+";
+
+    #[test]
+    fn certificate_verification() {
+        verify_key_cert(KEY, CERT).unwrap();
+    }
+
+    #[test]
+    #[should_panic(expected = "private key file does not match certificate")]
+    fn certificate_verification_fail() {
+        verify_key_cert(INCORRECT_KEY, CERT).unwrap();
+    }
+}
diff --git a/control_plane/src/bin/neon_local.rs b/control_plane/src/bin/neon_local.rs
index af0504b957..5cf6767361 100644
--- a/control_plane/src/bin/neon_local.rs
+++ b/control_plane/src/bin/neon_local.rs
@@ -18,12 +18,11 @@ use anyhow::{Context, Result, anyhow, bail};
 use clap::Parser;
 use compute_api::spec::ComputeMode;
 use control_plane::endpoint::ComputeControlPlane;
+use control_plane::endpoint_storage::{ENDPOINT_STORAGE_DEFAULT_PORT, EndpointStorage};
 use control_plane::local_env::{
-    InitForceMode, LocalEnv, NeonBroker, NeonLocalInitConf, NeonLocalInitPageserverConf,
-    ObjectStorageConf, SafekeeperConf,
+    EndpointStorageConf, InitForceMode, LocalEnv, NeonBroker, NeonLocalInitConf,
+    NeonLocalInitPageserverConf, SafekeeperConf,
 };
-use control_plane::object_storage::OBJECT_STORAGE_DEFAULT_PORT;
-use control_plane::object_storage::ObjectStorage;
 use control_plane::pageserver::PageServerNode;
 use control_plane::safekeeper::SafekeeperNode;
 use control_plane::storage_controller::{
@@ -93,7 +92,7 @@ enum NeonLocalCmd {
     #[command(subcommand)]
     Safekeeper(SafekeeperCmd),
     #[command(subcommand)]
-    ObjectStorage(ObjectStorageCmd),
+    EndpointStorage(EndpointStorageCmd),
     #[command(subcommand)]
     Endpoint(EndpointCmd),
     #[command(subcommand)]
@@ -460,14 +459,14 @@ enum SafekeeperCmd {
 
 #[derive(clap::Subcommand)]
 #[clap(about = "Manage object storage")]
-enum ObjectStorageCmd {
-    Start(ObjectStorageStartCmd),
-    Stop(ObjectStorageStopCmd),
+enum EndpointStorageCmd {
+    Start(EndpointStorageStartCmd),
+    Stop(EndpointStorageStopCmd),
 }
 
 #[derive(clap::Args)]
 #[clap(about = "Start object storage")]
-struct ObjectStorageStartCmd {
+struct EndpointStorageStartCmd {
     #[clap(short = 't', long, help = "timeout until we fail the command")]
     #[arg(default_value = "10s")]
     start_timeout: humantime::Duration,
@@ -475,7 +474,7 @@ struct ObjectStorageStartCmd {
 
 #[derive(clap::Args)]
 #[clap(about = "Stop object storage")]
-struct ObjectStorageStopCmd {
+struct EndpointStorageStopCmd {
     #[arg(value_enum, default_value = "fast")]
     #[clap(
         short = 'm',
@@ -797,7 +796,9 @@ fn main() -> Result<()> {
             }
             NeonLocalCmd::StorageBroker(subcmd) => rt.block_on(handle_storage_broker(&subcmd, env)),
             NeonLocalCmd::Safekeeper(subcmd) => rt.block_on(handle_safekeeper(&subcmd, env)),
-            NeonLocalCmd::ObjectStorage(subcmd) => rt.block_on(handle_object_storage(&subcmd, env)),
+            NeonLocalCmd::EndpointStorage(subcmd) => {
+                rt.block_on(handle_endpoint_storage(&subcmd, env))
+            }
             NeonLocalCmd::Endpoint(subcmd) => rt.block_on(handle_endpoint(&subcmd, env)),
             NeonLocalCmd::Mappings(subcmd) => handle_mappings(&subcmd, env),
         };
@@ -1014,8 +1015,8 @@ fn handle_init(args: &InitCmdArgs) -> anyhow::Result<LocalEnv> {
                     }
                 })
                 .collect(),
-            object_storage: ObjectStorageConf {
-                port: OBJECT_STORAGE_DEFAULT_PORT,
+            endpoint_storage: EndpointStorageConf {
+                port: ENDPOINT_STORAGE_DEFAULT_PORT,
             },
             pg_distrib_dir: None,
             neon_distrib_dir: None,
@@ -1735,12 +1736,15 @@ async fn handle_safekeeper(subcmd: &SafekeeperCmd, env: &local_env::LocalEnv) ->
     Ok(())
 }
 
-async fn handle_object_storage(subcmd: &ObjectStorageCmd, env: &local_env::LocalEnv) -> Result<()> {
-    use ObjectStorageCmd::*;
-    let storage = ObjectStorage::from_env(env);
+async fn handle_endpoint_storage(
+    subcmd: &EndpointStorageCmd,
+    env: &local_env::LocalEnv,
+) -> Result<()> {
+    use EndpointStorageCmd::*;
+    let storage = EndpointStorage::from_env(env);
 
     // In tests like test_forward_compatibility or test_graceful_cluster_restart
-    // old neon binaries (without object_storage) are present
+    // old neon binaries (without endpoint_storage) are present
     if !storage.bin.exists() {
         eprintln!(
             "{} binary not found. Ignore if this is a compatibility test",
@@ -1750,13 +1754,13 @@ async fn handle_object_storage(subcmd: &ObjectStorageCmd, env: &local_env::Local
     }
 
     match subcmd {
-        Start(ObjectStorageStartCmd { start_timeout }) => {
+        Start(EndpointStorageStartCmd { start_timeout }) => {
             if let Err(e) = storage.start(start_timeout).await {
-                eprintln!("object_storage start failed: {e}");
+                eprintln!("endpoint_storage start failed: {e}");
                 exit(1);
             }
         }
-        Stop(ObjectStorageStopCmd { stop_mode }) => {
+        Stop(EndpointStorageStopCmd { stop_mode }) => {
             let immediate = match stop_mode {
                 StopMode::Fast => false,
                 StopMode::Immediate => true,
@@ -1866,10 +1870,10 @@ async fn handle_start_all_impl(
         }
 
         js.spawn(async move {
-            ObjectStorage::from_env(env)
+            EndpointStorage::from_env(env)
                 .start(&retry_timeout)
                 .await
-                .map_err(|e| e.context("start object_storage"))
+                .map_err(|e| e.context("start endpoint_storage"))
         });
     })();
 
@@ -1968,9 +1972,9 @@ async fn try_stop_all(env: &local_env::LocalEnv, immediate: bool) {
         }
     }
 
-    let storage = ObjectStorage::from_env(env);
+    let storage = EndpointStorage::from_env(env);
     if let Err(e) = storage.stop(immediate) {
-        eprintln!("object_storage stop failed: {:#}", e);
+        eprintln!("endpoint_storage stop failed: {:#}", e);
     }
 
     for ps_conf in &env.pageservers {
diff --git a/control_plane/src/object_storage.rs b/control_plane/src/endpoint_storage.rs
similarity index 63%
rename from control_plane/src/object_storage.rs
rename to control_plane/src/endpoint_storage.rs
index 1a595b7809..102db91a22 100644
--- a/control_plane/src/object_storage.rs
+++ b/control_plane/src/endpoint_storage.rs
@@ -1,34 +1,33 @@
 use crate::background_process::{self, start_process, stop_process};
 use crate::local_env::LocalEnv;
-use anyhow::anyhow;
 use anyhow::{Context, Result};
 use camino::Utf8PathBuf;
 use std::io::Write;
 use std::time::Duration;
 
 /// Directory within .neon which will be used by default for LocalFs remote storage.
-pub const OBJECT_STORAGE_REMOTE_STORAGE_DIR: &str = "local_fs_remote_storage/object_storage";
-pub const OBJECT_STORAGE_DEFAULT_PORT: u16 = 9993;
+pub const ENDPOINT_STORAGE_REMOTE_STORAGE_DIR: &str = "local_fs_remote_storage/endpoint_storage";
+pub const ENDPOINT_STORAGE_DEFAULT_PORT: u16 = 9993;
 
-pub struct ObjectStorage {
+pub struct EndpointStorage {
     pub bin: Utf8PathBuf,
     pub data_dir: Utf8PathBuf,
     pub pemfile: Utf8PathBuf,
     pub port: u16,
 }
 
-impl ObjectStorage {
-    pub fn from_env(env: &LocalEnv) -> ObjectStorage {
-        ObjectStorage {
-            bin: Utf8PathBuf::from_path_buf(env.object_storage_bin()).unwrap(),
-            data_dir: Utf8PathBuf::from_path_buf(env.object_storage_data_dir()).unwrap(),
+impl EndpointStorage {
+    pub fn from_env(env: &LocalEnv) -> EndpointStorage {
+        EndpointStorage {
+            bin: Utf8PathBuf::from_path_buf(env.endpoint_storage_bin()).unwrap(),
+            data_dir: Utf8PathBuf::from_path_buf(env.endpoint_storage_data_dir()).unwrap(),
             pemfile: Utf8PathBuf::from_path_buf(env.public_key_path.clone()).unwrap(),
-            port: env.object_storage.port,
+            port: env.endpoint_storage.port,
         }
     }
 
     fn config_path(&self) -> Utf8PathBuf {
-        self.data_dir.join("object_storage.json")
+        self.data_dir.join("endpoint_storage.json")
     }
 
     fn listen_addr(&self) -> Utf8PathBuf {
@@ -49,7 +48,7 @@ impl ObjectStorage {
         let cfg = Cfg {
             listen: self.listen_addr(),
             pemfile: parent.join(self.pemfile.clone()),
-            local_path: parent.join(OBJECT_STORAGE_REMOTE_STORAGE_DIR),
+            local_path: parent.join(ENDPOINT_STORAGE_REMOTE_STORAGE_DIR),
             r#type: "LocalFs".to_string(),
         };
         std::fs::create_dir_all(self.config_path().parent().unwrap())?;
@@ -59,24 +58,19 @@ impl ObjectStorage {
     }
 
     pub async fn start(&self, retry_timeout: &Duration) -> Result<()> {
-        println!("Starting s3 proxy at {}", self.listen_addr());
+        println!("Starting endpoint_storage at {}", self.listen_addr());
         std::io::stdout().flush().context("flush stdout")?;
 
         let process_status_check = || async {
-            tokio::time::sleep(Duration::from_millis(500)).await;
-            let res = reqwest::Client::new()
-                .get(format!("http://{}/metrics", self.listen_addr()))
-                .send()
-                .await;
-            match res {
-                Ok(response) if response.status().is_success() => Ok(true),
-                Ok(_) => Err(anyhow!("Failed to query /metrics")),
-                Err(e) => Err(anyhow!("Failed to check node status: {e}")),
+            let res = reqwest::Client::new().get(format!("http://{}/metrics", self.listen_addr()));
+            match res.send().await {
+                Ok(res) => Ok(res.status().is_success()),
+                Err(_) => Ok(false),
             }
         };
 
         let res = start_process(
-            "object_storage",
+            "endpoint_storage",
             &self.data_dir.clone().into_std_path_buf(),
             &self.bin.clone().into_std_path_buf(),
             vec![self.config_path().to_string()],
@@ -94,14 +88,14 @@ impl ObjectStorage {
     }
 
     pub fn stop(&self, immediate: bool) -> anyhow::Result<()> {
-        stop_process(immediate, "object_storage", &self.pid_file())
+        stop_process(immediate, "endpoint_storage", &self.pid_file())
     }
 
     fn log_file(&self) -> Utf8PathBuf {
-        self.data_dir.join("object_storage.log")
+        self.data_dir.join("endpoint_storage.log")
     }
 
     fn pid_file(&self) -> Utf8PathBuf {
-        self.data_dir.join("object_storage.pid")
+        self.data_dir.join("endpoint_storage.pid")
     }
 }
diff --git a/control_plane/src/lib.rs b/control_plane/src/lib.rs
index 2d9fe2c807..4619bc0f13 100644
--- a/control_plane/src/lib.rs
+++ b/control_plane/src/lib.rs
@@ -9,8 +9,8 @@
 mod background_process;
 pub mod broker;
 pub mod endpoint;
+pub mod endpoint_storage;
 pub mod local_env;
-pub mod object_storage;
 pub mod pageserver;
 pub mod postgresql_conf;
 pub mod safekeeper;
diff --git a/control_plane/src/local_env.rs b/control_plane/src/local_env.rs
index 5e3cf95a31..77d5c1c922 100644
--- a/control_plane/src/local_env.rs
+++ b/control_plane/src/local_env.rs
@@ -19,7 +19,7 @@ use serde::{Deserialize, Serialize};
 use utils::auth::encode_from_key_file;
 use utils::id::{NodeId, TenantId, TenantTimelineId, TimelineId};
 
-use crate::object_storage::{OBJECT_STORAGE_REMOTE_STORAGE_DIR, ObjectStorage};
+use crate::endpoint_storage::{ENDPOINT_STORAGE_REMOTE_STORAGE_DIR, EndpointStorage};
 use crate::pageserver::{PAGESERVER_REMOTE_STORAGE_DIR, PageServerNode};
 use crate::safekeeper::SafekeeperNode;
 
@@ -72,7 +72,7 @@ pub struct LocalEnv {
 
     pub safekeepers: Vec<SafekeeperConf>,
 
-    pub object_storage: ObjectStorageConf,
+    pub endpoint_storage: EndpointStorageConf,
 
     // Control plane upcall API for pageserver: if None, we will not run storage_controller  If set, this will
     // be propagated into each pageserver's configuration.
@@ -110,7 +110,7 @@ pub struct OnDiskConfig {
     )]
     pub pageservers: Vec<PageServerConf>,
     pub safekeepers: Vec<SafekeeperConf>,
-    pub object_storage: ObjectStorageConf,
+    pub endpoint_storage: EndpointStorageConf,
     pub control_plane_api: Option<Url>,
     pub control_plane_hooks_api: Option<Url>,
     pub control_plane_compute_hook_api: Option<Url>,
@@ -144,7 +144,7 @@ pub struct NeonLocalInitConf {
     pub storage_controller: Option<NeonStorageControllerConf>,
     pub pageservers: Vec<NeonLocalInitPageserverConf>,
     pub safekeepers: Vec<SafekeeperConf>,
-    pub object_storage: ObjectStorageConf,
+    pub endpoint_storage: EndpointStorageConf,
     pub control_plane_api: Option<Url>,
     pub control_plane_hooks_api: Option<Url>,
     pub generate_local_ssl_certs: bool,
@@ -152,7 +152,7 @@ pub struct NeonLocalInitConf {
 
 #[derive(Serialize, Default, Deserialize, PartialEq, Eq, Clone, Debug)]
 #[serde(default)]
-pub struct ObjectStorageConf {
+pub struct EndpointStorageConf {
     pub port: u16,
 }
 
@@ -413,8 +413,8 @@ impl LocalEnv {
         self.pg_dir(pg_version, "lib")
     }
 
-    pub fn object_storage_bin(&self) -> PathBuf {
-        self.neon_distrib_dir.join("object_storage")
+    pub fn endpoint_storage_bin(&self) -> PathBuf {
+        self.neon_distrib_dir.join("endpoint_storage")
     }
 
     pub fn pageserver_bin(&self) -> PathBuf {
@@ -450,8 +450,8 @@ impl LocalEnv {
         self.base_data_dir.join("safekeepers").join(data_dir_name)
     }
 
-    pub fn object_storage_data_dir(&self) -> PathBuf {
-        self.base_data_dir.join("object_storage")
+    pub fn endpoint_storage_data_dir(&self) -> PathBuf {
+        self.base_data_dir.join("endpoint_storage")
     }
 
     pub fn get_pageserver_conf(&self, id: NodeId) -> anyhow::Result<&PageServerConf> {
@@ -615,7 +615,7 @@ impl LocalEnv {
                 control_plane_compute_hook_api: _,
                 branch_name_mappings,
                 generate_local_ssl_certs,
-                object_storage,
+                endpoint_storage,
             } = on_disk_config;
             LocalEnv {
                 base_data_dir: repopath.to_owned(),
@@ -632,7 +632,7 @@ impl LocalEnv {
                 control_plane_hooks_api,
                 branch_name_mappings,
                 generate_local_ssl_certs,
-                object_storage,
+                endpoint_storage,
             }
         };
 
@@ -742,7 +742,7 @@ impl LocalEnv {
                 control_plane_compute_hook_api: None,
                 branch_name_mappings: self.branch_name_mappings.clone(),
                 generate_local_ssl_certs: self.generate_local_ssl_certs,
-                object_storage: self.object_storage.clone(),
+                endpoint_storage: self.endpoint_storage.clone(),
             },
         )
     }
@@ -849,7 +849,7 @@ impl LocalEnv {
             control_plane_api,
             generate_local_ssl_certs,
             control_plane_hooks_api,
-            object_storage,
+            endpoint_storage,
         } = conf;
 
         // Find postgres binaries.
@@ -901,7 +901,7 @@ impl LocalEnv {
             control_plane_hooks_api,
             branch_name_mappings: Default::default(),
             generate_local_ssl_certs,
-            object_storage,
+            endpoint_storage,
         };
 
         if generate_local_ssl_certs {
@@ -929,13 +929,13 @@ impl LocalEnv {
                 .context("pageserver init failed")?;
         }
 
-        ObjectStorage::from_env(&env)
+        EndpointStorage::from_env(&env)
             .init()
             .context("object storage init failed")?;
 
         // setup remote remote location for default LocalFs remote storage
         std::fs::create_dir_all(env.base_data_dir.join(PAGESERVER_REMOTE_STORAGE_DIR))?;
-        std::fs::create_dir_all(env.base_data_dir.join(OBJECT_STORAGE_REMOTE_STORAGE_DIR))?;
+        std::fs::create_dir_all(env.base_data_dir.join(ENDPOINT_STORAGE_REMOTE_STORAGE_DIR))?;
 
         env.persist_config()
     }
diff --git a/deny.toml b/deny.toml
index ed7aa9ef9f..be1c6a2f2c 100644
--- a/deny.toml
+++ b/deny.toml
@@ -45,9 +45,7 @@ allow = [
     "ISC",
     "MIT",
     "MPL-2.0",
-    "OpenSSL",
     "Unicode-3.0",
-    "Zlib",
 ]
 confidence-threshold = 0.8
 exceptions = [
@@ -56,14 +54,6 @@ exceptions = [
     { allow = ["Zlib"], name = "const_format", version = "*" },
 ]
 
-[[licenses.clarify]]
-name = "ring"
-version = "*"
-expression = "MIT AND ISC AND OpenSSL"
-license-files = [
-    { path = "LICENSE", hash = 0xbd0eed23 }
-]
-
 [licenses.private]
 ignore = true
 registries = []
@@ -116,7 +106,11 @@ name = "openssl"
 unknown-registry = "warn"
 unknown-git = "warn"
 allow-registry = ["https://github.com/rust-lang/crates.io-index"]
-allow-git = []
+allow-git = [
+    # Crate pinned to commit in origin repo due to opentelemetry version.
+    # TODO: Remove this once crate is fetched from crates.io again.
+    "https://github.com/mattiapenati/tower-otel",
+]
 
 [sources.allow-org]
 github = [
diff --git a/docker-compose/docker_compose_test.sh b/docker-compose/docker_compose_test.sh
index 86aa86d4ec..c3b4d11947 100755
--- a/docker-compose/docker_compose_test.sh
+++ b/docker-compose/docker_compose_test.sh
@@ -9,21 +9,20 @@
 # to verify custom image builds (e.g pre-published ones).
 #
 # A test script for postgres extensions
-# Currently supports only v16
+# Currently supports only v16+
 #
 set -eux -o pipefail
 
-COMPOSE_FILE='docker-compose.yml'
-cd $(dirname $0)
-COMPUTE_CONTAINER_NAME=docker-compose-compute-1
-TEST_CONTAINER_NAME=docker-compose-neon-test-extensions-1
+export COMPOSE_FILE='docker-compose.yml'
+export COMPOSE_PROFILES=test-extensions
+cd "$(dirname "${0}")"
 PSQL_OPTION="-h localhost -U cloud_admin -p 55433 -d postgres"
 
-cleanup() {
+function cleanup() {
     echo "show container information"
     docker ps
     echo "stop containers..."
-    docker compose --profile test-extensions -f $COMPOSE_FILE down
+    docker compose down
 }
 
 for pg_version in ${TEST_VERSION_ONLY-14 15 16 17}; do
@@ -31,50 +30,57 @@ for pg_version in ${TEST_VERSION_ONLY-14 15 16 17}; do
     echo "clean up containers if exists"
     cleanup
     PG_TEST_VERSION=$((pg_version < 16 ? 16 : pg_version))
-    PG_VERSION=$pg_version PG_TEST_VERSION=$PG_TEST_VERSION docker compose --profile test-extensions -f $COMPOSE_FILE up --quiet-pull --build -d
+    PG_VERSION=${pg_version} PG_TEST_VERSION=${PG_TEST_VERSION} docker compose up --quiet-pull --build -d
 
     echo "wait until the compute is ready. timeout after 60s. "
     cnt=0
     while sleep 3; do
         # check timeout
-        cnt=`expr $cnt + 3`
-        if [ $cnt -gt 60 ]; then
+        (( cnt += 3 ))
+        if [[ ${cnt} -gt 60 ]]; then
             echo "timeout before the compute is ready."
             exit 1
         fi
-        if docker compose --profile test-extensions -f $COMPOSE_FILE logs "compute_is_ready" | grep -q "accepting connections"; then
+        if docker compose logs "compute_is_ready" | grep -q "accepting connections"; then
             echo "OK. The compute is ready to connect."
             echo "execute simple queries."
-            docker exec $COMPUTE_CONTAINER_NAME /bin/bash -c "psql $PSQL_OPTION"
+            docker compose exec compute /bin/bash -c "psql ${PSQL_OPTION} -c 'SELECT 1'"
             break
         fi
     done
 
-    if [ $pg_version -ge 16 ]; then
+    if [[ ${pg_version} -ge 16 ]]; then
         # This is required for the pg_hint_plan test, to prevent flaky log message causing the test to fail
         # It cannot be moved to Dockerfile now because the database directory is created after the start of the container
         echo Adding dummy config
-        docker exec $COMPUTE_CONTAINER_NAME touch /var/db/postgres/compute/compute_ctl_temp_override.conf
+        docker compose exec compute touch /var/db/postgres/compute/compute_ctl_temp_override.conf
         # The following block copies the files for the pg_hintplan test to the compute node for the extension test in an isolated docker-compose environment
         TMPDIR=$(mktemp -d)
-        docker cp $TEST_CONTAINER_NAME:/ext-src/pg_hint_plan-src/data $TMPDIR/data
-        docker cp $TMPDIR/data $COMPUTE_CONTAINER_NAME:/ext-src/pg_hint_plan-src/
-        rm -rf $TMPDIR
+        docker compose cp neon-test-extensions:/ext-src/pg_hint_plan-src/data "${TMPDIR}/data"
+        docker compose cp "${TMPDIR}/data" compute:/ext-src/pg_hint_plan-src/
+        rm -rf "${TMPDIR}"
         # The following block does the same for the contrib/file_fdw test
         TMPDIR=$(mktemp -d)
-        docker cp $TEST_CONTAINER_NAME:/postgres/contrib/file_fdw/data $TMPDIR/data
-        docker cp $TMPDIR/data $COMPUTE_CONTAINER_NAME:/postgres/contrib/file_fdw/data
-        rm -rf $TMPDIR
+        docker compose cp neon-test-extensions:/postgres/contrib/file_fdw/data "${TMPDIR}/data"
+        docker compose cp "${TMPDIR}/data" compute:/postgres/contrib/file_fdw/data
+        rm -rf "${TMPDIR}"
         # Apply patches
-        cat ../compute/patches/contrib_pg${pg_version}.patch | docker exec -i $TEST_CONTAINER_NAME bash -c "(cd /postgres && patch -p1)"
+        docker compose exec -i neon-test-extensions bash -c "(cd /postgres && patch -p1)" <"../compute/patches/contrib_pg${pg_version}.patch"
         # We are running tests now
         rm -f testout.txt testout_contrib.txt
-        docker exec -e USE_PGXS=1 -e SKIP=timescaledb-src,rdkit-src,postgis-src,pg_jsonschema-src,kq_imcx-src,wal2json_2_5-src,rag_jina_reranker_v1_tiny_en-src,rag_bge_small_en_v15-src \
-        $TEST_CONTAINER_NAME /run-tests.sh /ext-src | tee testout.txt && EXT_SUCCESS=1 || EXT_SUCCESS=0
-        docker exec -e SKIP=start-scripts,postgres_fdw,ltree_plpython,jsonb_plpython,jsonb_plperl,hstore_plpython,hstore_plperl,dblink,bool_plperl \
-        $TEST_CONTAINER_NAME /run-tests.sh /postgres/contrib | tee testout_contrib.txt && CONTRIB_SUCCESS=1 || CONTRIB_SUCCESS=0
-        if [ $EXT_SUCCESS -eq 0 ] || [ $CONTRIB_SUCCESS -eq 0 ]; then
-            exit 1
+        docker compose exec -e USE_PGXS=1 -e SKIP=timescaledb-src,rdkit-src,postgis-src,pg_jsonschema-src,kq_imcx-src,wal2json_2_5-src,rag_jina_reranker_v1_tiny_en-src,rag_bge_small_en_v15-src \
+        neon-test-extensions /run-tests.sh /ext-src | tee testout.txt && EXT_SUCCESS=1 || EXT_SUCCESS=0
+        docker compose exec -e SKIP=start-scripts,postgres_fdw,ltree_plpython,jsonb_plpython,jsonb_plperl,hstore_plpython,hstore_plperl,dblink,bool_plperl \
+        neon-test-extensions /run-tests.sh /postgres/contrib | tee testout_contrib.txt && CONTRIB_SUCCESS=1 || CONTRIB_SUCCESS=0
+        if [[ ${EXT_SUCCESS} -eq 0 || ${CONTRIB_SUCCESS} -eq 0 ]]; then
+            CONTRIB_FAILED=
+            FAILED=
+            [[ ${EXT_SUCCESS} -eq 0 ]] && FAILED=$(tail -1 testout.txt | awk '{for(i=1;i<=NF;i++){print "/ext-src/"$i;}}')
+            [[ ${CONTRIB_SUCCESS} -eq 0 ]] && CONTRIB_FAILED=$(tail -1 testout_contrib.txt | awk '{for(i=0;i<=NF;i++){print "/postgres/contrib/"$i;}}')
+            for d in ${FAILED} ${CONTRIB_FAILED}; do
+                docker compose exec neon-test-extensions bash -c 'for file in $(find '"${d}"' -name regression.diffs -o -name regression.out); do cat ${file}; done' || [[ ${?} -eq 1 ]]
+            done
+        exit 1
         fi
     fi
 done
diff --git a/object_storage/Cargo.toml b/endpoint_storage/Cargo.toml
similarity index 96%
rename from object_storage/Cargo.toml
rename to endpoint_storage/Cargo.toml
index 17fbaefe6f..b2c9d51551 100644
--- a/object_storage/Cargo.toml
+++ b/endpoint_storage/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "object_storage"
+name = "endpoint_storage"
 version = "0.0.1"
 edition.workspace = true
 license.workspace = true
diff --git a/object_storage/src/app.rs b/endpoint_storage/src/app.rs
similarity index 94%
rename from object_storage/src/app.rs
rename to endpoint_storage/src/app.rs
index 7b5627f0db..f07ef06328 100644
--- a/object_storage/src/app.rs
+++ b/endpoint_storage/src/app.rs
@@ -2,7 +2,7 @@ use anyhow::anyhow;
 use axum::body::{Body, Bytes};
 use axum::response::{IntoResponse, Response};
 use axum::{Router, http::StatusCode};
-use object_storage::{PrefixS3Path, S3Path, Storage, bad_request, internal_error, not_found, ok};
+use endpoint_storage::{PrefixS3Path, S3Path, Storage, bad_request, internal_error, not_found, ok};
 use remote_storage::TimeoutOrCancel;
 use remote_storage::{DownloadError, DownloadOpts, GenericRemoteStorage, RemotePath};
 use std::{sync::Arc, time::SystemTime, time::UNIX_EPOCH};
@@ -46,12 +46,12 @@ async fn metrics() -> Result {
 
 async fn get(S3Path { path }: S3Path, state: State) -> Result {
     info!(%path, "downloading");
-    let download_err = |e| {
-        if let DownloadError::NotFound = e {
-            info!(%path, %e, "downloading"); // 404 is not an issue of _this_ service
+    let download_err = |err| {
+        if let DownloadError::NotFound = err {
+            info!(%path, %err, "downloading"); // 404 is not an issue of _this_ service
             return not_found(&path);
         }
-        internal_error(e, &path, "downloading")
+        internal_error(err, &path, "downloading")
     };
     let cancel = state.cancel.clone();
     let opts = &DownloadOpts::default();
@@ -249,7 +249,7 @@ mod tests {
         };
 
         let proxy = Storage {
-            auth: object_storage::JwtAuth::new(TEST_PUB_KEY_ED25519).unwrap(),
+            auth: endpoint_storage::JwtAuth::new(TEST_PUB_KEY_ED25519).unwrap(),
             storage,
             cancel: cancel.clone(),
             max_upload_file_limit: usize::MAX,
@@ -343,14 +343,14 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
         TimelineId::from_array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 7]);
     const ENDPOINT_ID: &str = "ep-winter-frost-a662z3vg";
     fn token() -> String {
-        let claims = object_storage::Claims {
+        let claims = endpoint_storage::Claims {
             tenant_id: TENANT_ID,
             timeline_id: TIMELINE_ID,
             endpoint_id: ENDPOINT_ID.into(),
             exp: u64::MAX,
         };
         let key = jsonwebtoken::EncodingKey::from_ed_pem(TEST_PRIV_KEY_ED25519).unwrap();
-        let header = jsonwebtoken::Header::new(object_storage::VALIDATION_ALGO);
+        let header = jsonwebtoken::Header::new(endpoint_storage::VALIDATION_ALGO);
         jsonwebtoken::encode(&header, &claims, &key).unwrap()
     }
 
@@ -364,7 +364,10 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
             vec![TIMELINE_ID.to_string(), TimelineId::generate().to_string()],
             vec![ENDPOINT_ID, "ep-ololo"]
         )
-        .skip(1);
+        // first one is fully valid path, second path is valid for GET as
+        // read paths may have different endpoint if tenant and timeline matches
+        // (needed for prewarming RO->RW replica)
+        .skip(2);
 
         for ((uri, method), (tenant, timeline, endpoint)) in iproduct!(routes(), args) {
             info!(%uri, %method, %tenant, %timeline, %endpoint);
@@ -475,6 +478,16 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
         requests_chain(chain.into_iter(), |_| token()).await;
     }
 
+    #[testlog(tokio::test)]
+    async fn read_other_endpoint_data() {
+        let uri = format!("/{TENANT_ID}/{TIMELINE_ID}/other_endpoint/key");
+        let chain = vec![
+            (uri.clone(), "GET", "", StatusCode::NOT_FOUND, false),
+            (uri.clone(), "PUT", "", StatusCode::UNAUTHORIZED, false),
+        ];
+        requests_chain(chain.into_iter(), |_| token()).await;
+    }
+
     fn delete_prefix_token(uri: &str) -> String {
         use serde::Serialize;
         let parts = uri.split("/").collect::<Vec<&str>>();
@@ -482,7 +495,7 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
         struct PrefixClaims {
             tenant_id: TenantId,
             timeline_id: Option<TimelineId>,
-            endpoint_id: Option<object_storage::EndpointId>,
+            endpoint_id: Option<endpoint_storage::EndpointId>,
             exp: u64,
         }
         let claims = PrefixClaims {
@@ -492,7 +505,7 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
             exp: u64::MAX,
         };
         let key = jsonwebtoken::EncodingKey::from_ed_pem(TEST_PRIV_KEY_ED25519).unwrap();
-        let header = jsonwebtoken::Header::new(object_storage::VALIDATION_ALGO);
+        let header = jsonwebtoken::Header::new(endpoint_storage::VALIDATION_ALGO);
         jsonwebtoken::encode(&header, &claims, &key).unwrap()
     }
 
diff --git a/object_storage/src/lib.rs b/endpoint_storage/src/lib.rs
similarity index 96%
rename from object_storage/src/lib.rs
rename to endpoint_storage/src/lib.rs
index 989afd4c25..eb6b80c487 100644
--- a/object_storage/src/lib.rs
+++ b/endpoint_storage/src/lib.rs
@@ -169,10 +169,19 @@ impl FromRequestParts<Arc<Storage>> for S3Path {
             .auth
             .decode(bearer.token())
             .map_err(|e| bad_request(e, "decoding token"))?;
+
+        // Read paths may have different endpoint ids. For readonly -> readwrite replica
+        // prewarming, endpoint must read other endpoint's data.
+        let endpoint_id = if parts.method == axum::http::Method::GET {
+            claims.endpoint_id.clone()
+        } else {
+            path.endpoint_id.clone()
+        };
+
         let route = Claims {
             tenant_id: path.tenant_id,
             timeline_id: path.timeline_id,
-            endpoint_id: path.endpoint_id.clone(),
+            endpoint_id,
             exp: claims.exp,
         };
         if route != claims {
diff --git a/object_storage/src/main.rs b/endpoint_storage/src/main.rs
similarity index 88%
rename from object_storage/src/main.rs
rename to endpoint_storage/src/main.rs
index 40325db19d..3d1f05575d 100644
--- a/object_storage/src/main.rs
+++ b/endpoint_storage/src/main.rs
@@ -1,4 +1,4 @@
-//! `object_storage` is a service which provides API for uploading and downloading
+//! `endpoint_storage` is a service which provides API for uploading and downloading
 //! files. It is used by compute and control plane for accessing LFC prewarm data.
 //! This service is deployed either as a separate component or as part of compute image
 //! for large computes.
@@ -33,7 +33,7 @@ async fn main() -> anyhow::Result<()> {
 
     let config: String = std::env::args().skip(1).take(1).collect();
     if config.is_empty() {
-        anyhow::bail!("Usage: object_storage config.json")
+        anyhow::bail!("Usage: endpoint_storage config.json")
     }
     info!("Reading config from {config}");
     let config = std::fs::read_to_string(config.clone())?;
@@ -41,7 +41,7 @@ async fn main() -> anyhow::Result<()> {
     info!("Reading pemfile from {}", config.pemfile.clone());
     let pemfile = std::fs::read(config.pemfile.clone())?;
     info!("Loading public key from {}", config.pemfile.clone());
-    let auth = object_storage::JwtAuth::new(&pemfile)?;
+    let auth = endpoint_storage::JwtAuth::new(&pemfile)?;
 
     let listener = tokio::net::TcpListener::bind(config.listen).await.unwrap();
     info!("listening on {}", listener.local_addr().unwrap());
@@ -50,7 +50,7 @@ async fn main() -> anyhow::Result<()> {
     let cancel = tokio_util::sync::CancellationToken::new();
     app::check_storage_permissions(&storage, cancel.clone()).await?;
 
-    let proxy = std::sync::Arc::new(object_storage::Storage {
+    let proxy = std::sync::Arc::new(endpoint_storage::Storage {
         auth,
         storage,
         cancel: cancel.clone(),
diff --git a/libs/pageserver_api/src/config.rs b/libs/pageserver_api/src/config.rs
index b434696624..b64c42a808 100644
--- a/libs/pageserver_api/src/config.rs
+++ b/libs/pageserver_api/src/config.rs
@@ -181,6 +181,7 @@ pub struct ConfigToml {
     pub generate_unarchival_heatmap: Option<bool>,
     pub tracing: Option<Tracing>,
     pub enable_tls_page_service_api: bool,
+    pub dev_mode: bool,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
@@ -657,6 +658,7 @@ impl Default for ConfigToml {
             generate_unarchival_heatmap: None,
             tracing: None,
             enable_tls_page_service_api: false,
+            dev_mode: false,
         }
     }
 }
diff --git a/libs/pageserver_api/src/models.rs b/libs/pageserver_api/src/models.rs
index e367db614f..ff911499ab 100644
--- a/libs/pageserver_api/src/models.rs
+++ b/libs/pageserver_api/src/models.rs
@@ -320,6 +320,35 @@ pub struct TimelineCreateRequest {
     pub mode: TimelineCreateRequestMode,
 }
 
+impl TimelineCreateRequest {
+    pub fn mode_tag(&self) -> &'static str {
+        match &self.mode {
+            TimelineCreateRequestMode::Branch { .. } => "branch",
+            TimelineCreateRequestMode::ImportPgdata { .. } => "import",
+            TimelineCreateRequestMode::Bootstrap { .. } => "bootstrap",
+        }
+    }
+
+    pub fn is_import(&self) -> bool {
+        matches!(self.mode, TimelineCreateRequestMode::ImportPgdata { .. })
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+pub enum ShardImportStatus {
+    InProgress,
+    Done,
+    Error(String),
+}
+impl ShardImportStatus {
+    pub fn is_terminal(&self) -> bool {
+        match self {
+            ShardImportStatus::InProgress => false,
+            ShardImportStatus::Done | ShardImportStatus::Error(_) => true,
+        }
+    }
+}
+
 /// Storage controller specific extensions to [`TimelineInfo`].
 #[derive(Serialize, Deserialize, Clone)]
 pub struct TimelineCreateResponseStorcon {
@@ -1774,6 +1803,8 @@ pub struct TopTenantShardsResponse {
 }
 
 pub mod virtual_file {
+    use std::sync::LazyLock;
+
     #[derive(
         Copy,
         Clone,
@@ -1811,35 +1842,33 @@ pub mod virtual_file {
     pub enum IoMode {
         /// Uses buffered IO.
         Buffered,
-        /// Uses direct IO, error out if the operation fails.
+        /// Uses direct IO for reads only.
         #[cfg(target_os = "linux")]
         Direct,
+        /// Use direct IO for reads and writes.
+        #[cfg(target_os = "linux")]
+        DirectRw,
     }
 
     impl IoMode {
         pub fn preferred() -> Self {
             // The default behavior when running Rust unit tests without any further
-            // flags is to use the newest behavior if available on the platform (Direct).
+            // flags is to use the newest behavior (DirectRw).
             // The CI uses the following environment variable to unit tests for all
             // different modes.
             // NB: the Python regression & perf tests have their own defaults management
             // that writes pageserver.toml; they do not use this variable.
             if cfg!(test) {
-                use once_cell::sync::Lazy;
-                static CACHED: Lazy<IoMode> = Lazy::new(|| {
+                static CACHED: LazyLock<IoMode> = LazyLock::new(|| {
                     utils::env::var_serde_json_string(
                         "NEON_PAGESERVER_UNIT_TEST_VIRTUAL_FILE_IO_MODE",
                     )
-                    .unwrap_or({
+                    .unwrap_or(
                         #[cfg(target_os = "linux")]
-                        {
-                            IoMode::Direct
-                        }
+                        IoMode::DirectRw,
                         #[cfg(not(target_os = "linux"))]
-                        {
-                            IoMode::Buffered
-                        }
-                    })
+                        IoMode::Buffered,
+                    )
                 });
                 *CACHED
             } else {
@@ -1856,6 +1885,8 @@ pub mod virtual_file {
                 v if v == (IoMode::Buffered as u8) => IoMode::Buffered,
                 #[cfg(target_os = "linux")]
                 v if v == (IoMode::Direct as u8) => IoMode::Direct,
+                #[cfg(target_os = "linux")]
+                v if v == (IoMode::DirectRw as u8) => IoMode::DirectRw,
                 x => return Err(x),
             })
         }
diff --git a/libs/pageserver_api/src/upcall_api.rs b/libs/pageserver_api/src/upcall_api.rs
index 285ba06056..7ee63f9036 100644
--- a/libs/pageserver_api/src/upcall_api.rs
+++ b/libs/pageserver_api/src/upcall_api.rs
@@ -4,10 +4,10 @@
 //! See docs/rfcs/025-generation-numbers.md
 
 use serde::{Deserialize, Serialize};
-use utils::id::NodeId;
+use utils::id::{NodeId, TimelineId};
 
 use crate::controller_api::NodeRegisterRequest;
-use crate::models::LocationConfigMode;
+use crate::models::{LocationConfigMode, ShardImportStatus};
 use crate::shard::TenantShardId;
 
 /// Upcall message sent by the pageserver to the configured `control_plane_api` on
@@ -62,3 +62,10 @@ pub struct ValidateResponseTenant {
     pub id: TenantShardId,
     pub valid: bool,
 }
+
+#[derive(Serialize, Deserialize)]
+pub struct PutTimelineImportStatusRequest {
+    pub tenant_shard_id: TenantShardId,
+    pub timeline_id: TimelineId,
+    pub status: ShardImportStatus,
+}
diff --git a/libs/remote_storage/src/azure_blob.rs b/libs/remote_storage/src/azure_blob.rs
index 18146c5464..a5cddb840f 100644
--- a/libs/remote_storage/src/azure_blob.rs
+++ b/libs/remote_storage/src/azure_blob.rs
@@ -14,8 +14,9 @@ use anyhow::{Context, Result};
 use azure_core::request_options::{IfMatchCondition, MaxResults, Metadata, Range};
 use azure_core::{Continuable, HttpClient, RetryOptions, TransportOptions};
 use azure_storage::StorageCredentials;
-use azure_storage_blobs::blob::CopyStatus;
 use azure_storage_blobs::blob::operations::GetBlobBuilder;
+use azure_storage_blobs::blob::{Blob, CopyStatus};
+use azure_storage_blobs::container::operations::ListBlobsBuilder;
 use azure_storage_blobs::prelude::{ClientBuilder, ContainerClient};
 use bytes::Bytes;
 use futures::FutureExt;
@@ -253,53 +254,15 @@ impl AzureBlobStorage {
         download
     }
 
-    async fn permit(
-        &self,
-        kind: RequestKind,
-        cancel: &CancellationToken,
-    ) -> Result<tokio::sync::SemaphorePermit<'_>, Cancelled> {
-        let acquire = self.concurrency_limiter.acquire(kind);
-
-        tokio::select! {
-            permit = acquire => Ok(permit.expect("never closed")),
-            _ = cancel.cancelled() => Err(Cancelled),
-        }
-    }
-
-    pub fn container_name(&self) -> &str {
-        &self.container_name
-    }
-}
-
-fn to_azure_metadata(metadata: StorageMetadata) -> Metadata {
-    let mut res = Metadata::new();
-    for (k, v) in metadata.0.into_iter() {
-        res.insert(k, v);
-    }
-    res
-}
-
-fn to_download_error(error: azure_core::Error) -> DownloadError {
-    if let Some(http_err) = error.as_http_error() {
-        match http_err.status() {
-            StatusCode::NotFound => DownloadError::NotFound,
-            StatusCode::NotModified => DownloadError::Unmodified,
-            StatusCode::BadRequest => DownloadError::BadInput(anyhow::Error::new(error)),
-            _ => DownloadError::Other(anyhow::Error::new(error)),
-        }
-    } else {
-        DownloadError::Other(error.into())
-    }
-}
-
-impl RemoteStorage for AzureBlobStorage {
-    fn list_streaming(
+    fn list_streaming_for_fn<T: Default + ListingCollector>(
         &self,
         prefix: Option<&RemotePath>,
         mode: ListingMode,
         max_keys: Option<NonZeroU32>,
         cancel: &CancellationToken,
-    ) -> impl Stream<Item = Result<Listing, DownloadError>> {
+        request_kind: RequestKind,
+        customize_builder: impl Fn(ListBlobsBuilder) -> ListBlobsBuilder,
+    ) -> impl Stream<Item = Result<T, DownloadError>> {
         // get the passed prefix or if it is not set use prefix_in_bucket value
         let list_prefix = prefix.map(|p| self.relative_path_to_name(p)).or_else(|| {
             self.prefix_in_container.clone().map(|mut s| {
@@ -311,7 +274,7 @@ impl RemoteStorage for AzureBlobStorage {
         });
 
         async_stream::stream! {
-            let _permit = self.permit(RequestKind::List, cancel).await?;
+            let _permit = self.permit(request_kind, cancel).await?;
 
             let mut builder = self.client.list_blobs();
 
@@ -327,6 +290,8 @@ impl RemoteStorage for AzureBlobStorage {
                 builder = builder.max_results(MaxResults::new(limit));
             }
 
+            builder = customize_builder(builder);
+
             let mut next_marker = None;
 
             let mut timeout_try_cnt = 1;
@@ -382,26 +347,20 @@ impl RemoteStorage for AzureBlobStorage {
                     break;
                 };
 
-                let mut res = Listing::default();
+                let mut res = T::default();
                 next_marker = entry.continuation();
                 let prefix_iter = entry
                     .blobs
                     .prefixes()
                     .map(|prefix| self.name_to_relative_path(&prefix.name));
-                res.prefixes.extend(prefix_iter);
+                res.add_prefixes(self, prefix_iter);
 
                 let blob_iter = entry
                     .blobs
-                    .blobs()
-                    .map(|k| ListingObject{
-                        key: self.name_to_relative_path(&k.name),
-                        last_modified: k.properties.last_modified.into(),
-                        size: k.properties.content_length,
-                    }
-                );
+                    .blobs();
 
                 for key in blob_iter {
-                    res.keys.push(key);
+                    res.add_blob(self, key);
 
                     if let Some(mut mk) = max_keys {
                         assert!(mk > 0);
@@ -423,6 +382,128 @@ impl RemoteStorage for AzureBlobStorage {
         }
     }
 
+    async fn permit(
+        &self,
+        kind: RequestKind,
+        cancel: &CancellationToken,
+    ) -> Result<tokio::sync::SemaphorePermit<'_>, Cancelled> {
+        let acquire = self.concurrency_limiter.acquire(kind);
+
+        tokio::select! {
+            permit = acquire => Ok(permit.expect("never closed")),
+            _ = cancel.cancelled() => Err(Cancelled),
+        }
+    }
+
+    pub fn container_name(&self) -> &str {
+        &self.container_name
+    }
+}
+
+trait ListingCollector {
+    fn add_prefixes(&mut self, abs: &AzureBlobStorage, prefix_it: impl Iterator<Item = RemotePath>);
+    fn add_blob(&mut self, abs: &AzureBlobStorage, blob: &Blob);
+}
+
+impl ListingCollector for Listing {
+    fn add_prefixes(
+        &mut self,
+        _abs: &AzureBlobStorage,
+        prefix_it: impl Iterator<Item = RemotePath>,
+    ) {
+        self.prefixes.extend(prefix_it);
+    }
+    fn add_blob(&mut self, abs: &AzureBlobStorage, blob: &Blob) {
+        self.keys.push(ListingObject {
+            key: abs.name_to_relative_path(&blob.name),
+            last_modified: blob.properties.last_modified.into(),
+            size: blob.properties.content_length,
+        });
+    }
+}
+
+impl ListingCollector for crate::VersionListing {
+    fn add_prefixes(
+        &mut self,
+        _abs: &AzureBlobStorage,
+        _prefix_it: impl Iterator<Item = RemotePath>,
+    ) {
+        // nothing
+    }
+    fn add_blob(&mut self, abs: &AzureBlobStorage, blob: &Blob) {
+        let id = crate::VersionId(blob.version_id.clone().expect("didn't find version ID"));
+        self.versions.push(crate::Version {
+            key: abs.name_to_relative_path(&blob.name),
+            last_modified: blob.properties.last_modified.into(),
+            kind: crate::VersionKind::Version(id),
+        });
+    }
+}
+
+fn to_azure_metadata(metadata: StorageMetadata) -> Metadata {
+    let mut res = Metadata::new();
+    for (k, v) in metadata.0.into_iter() {
+        res.insert(k, v);
+    }
+    res
+}
+
+fn to_download_error(error: azure_core::Error) -> DownloadError {
+    if let Some(http_err) = error.as_http_error() {
+        match http_err.status() {
+            StatusCode::NotFound => DownloadError::NotFound,
+            StatusCode::NotModified => DownloadError::Unmodified,
+            StatusCode::BadRequest => DownloadError::BadInput(anyhow::Error::new(error)),
+            _ => DownloadError::Other(anyhow::Error::new(error)),
+        }
+    } else {
+        DownloadError::Other(error.into())
+    }
+}
+
+impl RemoteStorage for AzureBlobStorage {
+    fn list_streaming(
+        &self,
+        prefix: Option<&RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &CancellationToken,
+    ) -> impl Stream<Item = Result<Listing, DownloadError>> {
+        let customize_builder = |builder| builder;
+        let kind = RequestKind::ListVersions;
+        self.list_streaming_for_fn(prefix, mode, max_keys, cancel, kind, customize_builder)
+    }
+
+    async fn list_versions(
+        &self,
+        prefix: Option<&RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &CancellationToken,
+    ) -> std::result::Result<crate::VersionListing, DownloadError> {
+        let customize_builder = |mut builder: ListBlobsBuilder| {
+            builder = builder.include_versions(true);
+            builder
+        };
+        let kind = RequestKind::ListVersions;
+
+        let mut stream = std::pin::pin!(self.list_streaming_for_fn(
+            prefix,
+            mode,
+            max_keys,
+            cancel,
+            kind,
+            customize_builder
+        ));
+        let mut combined: crate::VersionListing =
+            stream.next().await.expect("At least one item required")?;
+        while let Some(list) = stream.next().await {
+            let list = list?;
+            combined.versions.extend(list.versions.into_iter());
+        }
+        Ok(combined)
+    }
+
     async fn head_object(
         &self,
         key: &RemotePath,
@@ -532,7 +613,12 @@ impl RemoteStorage for AzureBlobStorage {
         let mut builder = blob_client.get();
 
         if let Some(ref etag) = opts.etag {
-            builder = builder.if_match(IfMatchCondition::NotMatch(etag.to_string()))
+            builder = builder.if_match(IfMatchCondition::NotMatch(etag.to_string()));
+        }
+
+        if let Some(ref version_id) = opts.version_id {
+            let version_id = azure_storage_blobs::prelude::VersionId::new(version_id.0.clone());
+            builder = builder.blob_versioning(version_id);
         }
 
         if let Some((start, end)) = opts.byte_range() {
diff --git a/libs/remote_storage/src/lib.rs b/libs/remote_storage/src/lib.rs
index 6eb5570d9b..b265d37a62 100644
--- a/libs/remote_storage/src/lib.rs
+++ b/libs/remote_storage/src/lib.rs
@@ -176,6 +176,32 @@ pub struct Listing {
     pub keys: Vec<ListingObject>,
 }
 
+#[derive(Default)]
+pub struct VersionListing {
+    pub versions: Vec<Version>,
+}
+
+pub struct Version {
+    pub key: RemotePath,
+    pub last_modified: SystemTime,
+    pub kind: VersionKind,
+}
+
+impl Version {
+    pub fn version_id(&self) -> Option<&VersionId> {
+        match &self.kind {
+            VersionKind::Version(id) => Some(id),
+            VersionKind::DeletionMarker => None,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum VersionKind {
+    DeletionMarker,
+    Version(VersionId),
+}
+
 /// Options for downloads. The default value is a plain GET.
 pub struct DownloadOpts {
     /// If given, returns [`DownloadError::Unmodified`] if the object still has
@@ -186,6 +212,8 @@ pub struct DownloadOpts {
     /// The end of the byte range to download, or unbounded. Must be after the
     /// start bound.
     pub byte_end: Bound<u64>,
+    /// Optionally request a specific version of a key
+    pub version_id: Option<VersionId>,
     /// Indicate whether we're downloading something small or large: this indirectly controls
     /// timeouts: for something like an index/manifest/heatmap, we should time out faster than
     /// for layer files
@@ -197,12 +225,16 @@ pub enum DownloadKind {
     Small,
 }
 
+#[derive(Debug, Clone)]
+pub struct VersionId(pub String);
+
 impl Default for DownloadOpts {
     fn default() -> Self {
         Self {
             etag: Default::default(),
             byte_start: Bound::Unbounded,
             byte_end: Bound::Unbounded,
+            version_id: None,
             kind: DownloadKind::Large,
         }
     }
@@ -295,6 +327,14 @@ pub trait RemoteStorage: Send + Sync + 'static {
         Ok(combined)
     }
 
+    async fn list_versions(
+        &self,
+        prefix: Option<&RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &CancellationToken,
+    ) -> Result<VersionListing, DownloadError>;
+
     /// Obtain metadata information about an object.
     async fn head_object(
         &self,
@@ -475,6 +515,22 @@ impl<Other: RemoteStorage> GenericRemoteStorage<Arc<Other>> {
         }
     }
 
+    // See [`RemoteStorage::list_versions`].
+    pub async fn list_versions<'a>(
+        &'a self,
+        prefix: Option<&'a RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &'a CancellationToken,
+    ) -> Result<VersionListing, DownloadError> {
+        match self {
+            Self::LocalFs(s) => s.list_versions(prefix, mode, max_keys, cancel).await,
+            Self::AwsS3(s) => s.list_versions(prefix, mode, max_keys, cancel).await,
+            Self::AzureBlob(s) => s.list_versions(prefix, mode, max_keys, cancel).await,
+            Self::Unreliable(s) => s.list_versions(prefix, mode, max_keys, cancel).await,
+        }
+    }
+
     // See [`RemoteStorage::head_object`].
     pub async fn head_object(
         &self,
@@ -727,6 +783,7 @@ impl ConcurrencyLimiter {
             RequestKind::Copy => &self.write,
             RequestKind::TimeTravel => &self.write,
             RequestKind::Head => &self.read,
+            RequestKind::ListVersions => &self.read,
         }
     }
 
diff --git a/libs/remote_storage/src/local_fs.rs b/libs/remote_storage/src/local_fs.rs
index f03d6ac8ee..6607b55f1a 100644
--- a/libs/remote_storage/src/local_fs.rs
+++ b/libs/remote_storage/src/local_fs.rs
@@ -445,6 +445,16 @@ impl RemoteStorage for LocalFs {
         }
     }
 
+    async fn list_versions(
+        &self,
+        _prefix: Option<&RemotePath>,
+        _mode: ListingMode,
+        _max_keys: Option<NonZeroU32>,
+        _cancel: &CancellationToken,
+    ) -> Result<crate::VersionListing, DownloadError> {
+        unimplemented!()
+    }
+
     async fn head_object(
         &self,
         key: &RemotePath,
diff --git a/libs/remote_storage/src/metrics.rs b/libs/remote_storage/src/metrics.rs
index 81e68e9a29..50d9823a8e 100644
--- a/libs/remote_storage/src/metrics.rs
+++ b/libs/remote_storage/src/metrics.rs
@@ -14,6 +14,7 @@ pub(crate) enum RequestKind {
     Copy = 4,
     TimeTravel = 5,
     Head = 6,
+    ListVersions = 7,
 }
 
 use RequestKind::*;
@@ -29,6 +30,7 @@ impl RequestKind {
             Copy => "copy_object",
             TimeTravel => "time_travel_recover",
             Head => "head_object",
+            ListVersions => "list_versions",
         }
     }
     const fn as_index(&self) -> usize {
@@ -36,7 +38,10 @@ impl RequestKind {
     }
 }
 
-const REQUEST_KIND_COUNT: usize = 7;
+const REQUEST_KIND_LIST: &[RequestKind] =
+    &[Get, Put, Delete, List, Copy, TimeTravel, Head, ListVersions];
+
+const REQUEST_KIND_COUNT: usize = REQUEST_KIND_LIST.len();
 pub(crate) struct RequestTyped<C>([C; REQUEST_KIND_COUNT]);
 
 impl<C> RequestTyped<C> {
@@ -45,12 +50,11 @@ impl<C> RequestTyped<C> {
     }
 
     fn build_with(mut f: impl FnMut(RequestKind) -> C) -> Self {
-        use RequestKind::*;
-        let mut it = [Get, Put, Delete, List, Copy, TimeTravel, Head].into_iter();
+        let mut it = REQUEST_KIND_LIST.iter();
         let arr = std::array::from_fn::<C, REQUEST_KIND_COUNT, _>(|index| {
             let next = it.next().unwrap();
             assert_eq!(index, next.as_index());
-            f(next)
+            f(*next)
         });
 
         if let Some(next) = it.next() {
diff --git a/libs/remote_storage/src/s3_bucket.rs b/libs/remote_storage/src/s3_bucket.rs
index ba7ce9e1e7..918d9d5a6b 100644
--- a/libs/remote_storage/src/s3_bucket.rs
+++ b/libs/remote_storage/src/s3_bucket.rs
@@ -21,9 +21,8 @@ use aws_sdk_s3::config::{AsyncSleep, IdentityCache, Region, SharedAsyncSleep};
 use aws_sdk_s3::error::SdkError;
 use aws_sdk_s3::operation::get_object::GetObjectError;
 use aws_sdk_s3::operation::head_object::HeadObjectError;
-use aws_sdk_s3::types::{Delete, DeleteMarkerEntry, ObjectIdentifier, ObjectVersion, StorageClass};
+use aws_sdk_s3::types::{Delete, ObjectIdentifier, StorageClass};
 use aws_smithy_async::rt::sleep::TokioSleep;
-use aws_smithy_types::DateTime;
 use aws_smithy_types::body::SdkBody;
 use aws_smithy_types::byte_stream::ByteStream;
 use aws_smithy_types::date_time::ConversionError;
@@ -46,7 +45,7 @@ use crate::support::PermitCarrying;
 use crate::{
     ConcurrencyLimiter, Download, DownloadError, DownloadOpts, Listing, ListingMode, ListingObject,
     MAX_KEYS_PER_DELETE_S3, REMOTE_STORAGE_PREFIX_SEPARATOR, RemotePath, RemoteStorage,
-    TimeTravelError, TimeoutOrCancel,
+    TimeTravelError, TimeoutOrCancel, Version, VersionId, VersionKind, VersionListing,
 };
 
 /// AWS S3 storage.
@@ -66,6 +65,7 @@ struct GetObjectRequest {
     key: String,
     etag: Option<String>,
     range: Option<String>,
+    version_id: Option<String>,
 }
 impl S3Bucket {
     /// Creates the S3 storage, errors if incorrect AWS S3 configuration provided.
@@ -251,6 +251,7 @@ impl S3Bucket {
             .get_object()
             .bucket(request.bucket)
             .key(request.key)
+            .set_version_id(request.version_id)
             .set_range(request.range);
 
         if let Some(etag) = request.etag {
@@ -405,6 +406,124 @@ impl S3Bucket {
         Ok(())
     }
 
+    async fn list_versions_with_permit(
+        &self,
+        _permit: &tokio::sync::SemaphorePermit<'_>,
+        prefix: Option<&RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &CancellationToken,
+    ) -> Result<crate::VersionListing, DownloadError> {
+        // get the passed prefix or if it is not set use prefix_in_bucket value
+        let prefix = prefix
+            .map(|p| self.relative_path_to_s3_object(p))
+            .or_else(|| self.prefix_in_bucket.clone());
+
+        let warn_threshold = 3;
+        let max_retries = 10;
+        let is_permanent = |e: &_| matches!(e, DownloadError::Cancelled);
+
+        let mut key_marker = None;
+        let mut version_id_marker = None;
+        let mut versions_and_deletes = Vec::new();
+
+        loop {
+            let response = backoff::retry(
+                || async {
+                    let mut request = self
+                        .client
+                        .list_object_versions()
+                        .bucket(self.bucket_name.clone())
+                        .set_prefix(prefix.clone())
+                        .set_key_marker(key_marker.clone())
+                        .set_version_id_marker(version_id_marker.clone());
+
+                    if let ListingMode::WithDelimiter = mode {
+                        request = request.delimiter(REMOTE_STORAGE_PREFIX_SEPARATOR.to_string());
+                    }
+
+                    let op = request.send();
+
+                    tokio::select! {
+                        res = op => res.map_err(|e| DownloadError::Other(e.into())),
+                        _ = cancel.cancelled() => Err(DownloadError::Cancelled),
+                    }
+                },
+                is_permanent,
+                warn_threshold,
+                max_retries,
+                "listing object versions",
+                cancel,
+            )
+            .await
+            .ok_or_else(|| DownloadError::Cancelled)
+            .and_then(|x| x)?;
+
+            tracing::trace!(
+                "  Got List response version_id_marker={:?}, key_marker={:?}",
+                response.version_id_marker,
+                response.key_marker
+            );
+            let versions = response
+                .versions
+                .unwrap_or_default()
+                .into_iter()
+                .map(|version| {
+                    let key = version.key.expect("response does not contain a key");
+                    let key = self.s3_object_to_relative_path(&key);
+                    let version_id = VersionId(version.version_id.expect("needing version id"));
+                    let last_modified =
+                        SystemTime::try_from(version.last_modified.expect("no last_modified"))?;
+                    Ok(Version {
+                        key,
+                        last_modified,
+                        kind: crate::VersionKind::Version(version_id),
+                    })
+                });
+            let deletes = response
+                .delete_markers
+                .unwrap_or_default()
+                .into_iter()
+                .map(|version| {
+                    let key = version.key.expect("response does not contain a key");
+                    let key = self.s3_object_to_relative_path(&key);
+                    let last_modified =
+                        SystemTime::try_from(version.last_modified.expect("no last_modified"))?;
+                    Ok(Version {
+                        key,
+                        last_modified,
+                        kind: crate::VersionKind::DeletionMarker,
+                    })
+                });
+            itertools::process_results(versions.chain(deletes), |n_vds| {
+                versions_and_deletes.extend(n_vds)
+            })
+            .map_err(DownloadError::Other)?;
+            fn none_if_empty(v: Option<String>) -> Option<String> {
+                v.filter(|v| !v.is_empty())
+            }
+            version_id_marker = none_if_empty(response.next_version_id_marker);
+            key_marker = none_if_empty(response.next_key_marker);
+            if version_id_marker.is_none() {
+                // The final response is not supposed to be truncated
+                if response.is_truncated.unwrap_or_default() {
+                    return Err(DownloadError::Other(anyhow::anyhow!(
+                        "Received truncated ListObjectVersions response for prefix={prefix:?}"
+                    )));
+                }
+                break;
+            }
+            if let Some(max_keys) = max_keys {
+                if versions_and_deletes.len() >= max_keys.get().try_into().unwrap() {
+                    return Err(DownloadError::Other(anyhow::anyhow!("too many versions")));
+                }
+            }
+        }
+        Ok(VersionListing {
+            versions: versions_and_deletes,
+        })
+    }
+
     pub fn bucket_name(&self) -> &str {
         &self.bucket_name
     }
@@ -621,6 +740,19 @@ impl RemoteStorage for S3Bucket {
         }
     }
 
+    async fn list_versions(
+        &self,
+        prefix: Option<&RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &CancellationToken,
+    ) -> Result<crate::VersionListing, DownloadError> {
+        let kind = RequestKind::ListVersions;
+        let permit = self.permit(kind, cancel).await?;
+        self.list_versions_with_permit(&permit, prefix, mode, max_keys, cancel)
+            .await
+    }
+
     async fn head_object(
         &self,
         key: &RemotePath,
@@ -801,6 +933,7 @@ impl RemoteStorage for S3Bucket {
                 key: self.relative_path_to_s3_object(from),
                 etag: opts.etag.as_ref().map(|e| e.to_string()),
                 range: opts.byte_range_header(),
+                version_id: opts.version_id.as_ref().map(|v| v.0.to_owned()),
             },
             cancel,
         )
@@ -845,94 +978,25 @@ impl RemoteStorage for S3Bucket {
         let kind = RequestKind::TimeTravel;
         let permit = self.permit(kind, cancel).await?;
 
-        let timestamp = DateTime::from(timestamp);
-        let done_if_after = DateTime::from(done_if_after);
-
         tracing::trace!("Target time: {timestamp:?}, done_if_after {done_if_after:?}");
 
-        // get the passed prefix or if it is not set use prefix_in_bucket value
-        let prefix = prefix
-            .map(|p| self.relative_path_to_s3_object(p))
-            .or_else(|| self.prefix_in_bucket.clone());
+        // Limit the number of versions deletions, mostly so that we don't
+        // keep requesting forever if the list is too long, as we'd put the
+        // list in RAM.
+        // Building a list of 100k entries that reaches the limit roughly takes
+        // 40 seconds, and roughly corresponds to tenants of 2 TiB physical size.
+        const COMPLEXITY_LIMIT: Option<NonZeroU32> = NonZeroU32::new(100_000);
 
-        let warn_threshold = 3;
-        let max_retries = 10;
-        let is_permanent = |e: &_| matches!(e, TimeTravelError::Cancelled);
-
-        let mut key_marker = None;
-        let mut version_id_marker = None;
-        let mut versions_and_deletes = Vec::new();
-
-        loop {
-            let response = backoff::retry(
-                || async {
-                    let op = self
-                        .client
-                        .list_object_versions()
-                        .bucket(self.bucket_name.clone())
-                        .set_prefix(prefix.clone())
-                        .set_key_marker(key_marker.clone())
-                        .set_version_id_marker(version_id_marker.clone())
-                        .send();
-
-                    tokio::select! {
-                        res = op => res.map_err(|e| TimeTravelError::Other(e.into())),
-                        _ = cancel.cancelled() => Err(TimeTravelError::Cancelled),
-                    }
-                },
-                is_permanent,
-                warn_threshold,
-                max_retries,
-                "listing object versions for time_travel_recover",
-                cancel,
-            )
+        let mode = ListingMode::NoDelimiter;
+        let version_listing = self
+            .list_versions_with_permit(&permit, prefix, mode, COMPLEXITY_LIMIT, cancel)
             .await
-            .ok_or_else(|| TimeTravelError::Cancelled)
-            .and_then(|x| x)?;
-
-            tracing::trace!(
-                "  Got List response version_id_marker={:?}, key_marker={:?}",
-                response.version_id_marker,
-                response.key_marker
-            );
-            let versions = response
-                .versions
-                .unwrap_or_default()
-                .into_iter()
-                .map(VerOrDelete::from_version);
-            let deletes = response
-                .delete_markers
-                .unwrap_or_default()
-                .into_iter()
-                .map(VerOrDelete::from_delete_marker);
-            itertools::process_results(versions.chain(deletes), |n_vds| {
-                versions_and_deletes.extend(n_vds)
-            })
-            .map_err(TimeTravelError::Other)?;
-            fn none_if_empty(v: Option<String>) -> Option<String> {
-                v.filter(|v| !v.is_empty())
-            }
-            version_id_marker = none_if_empty(response.next_version_id_marker);
-            key_marker = none_if_empty(response.next_key_marker);
-            if version_id_marker.is_none() {
-                // The final response is not supposed to be truncated
-                if response.is_truncated.unwrap_or_default() {
-                    return Err(TimeTravelError::Other(anyhow::anyhow!(
-                        "Received truncated ListObjectVersions response for prefix={prefix:?}"
-                    )));
-                }
-                break;
-            }
-            // Limit the number of versions deletions, mostly so that we don't
-            // keep requesting forever if the list is too long, as we'd put the
-            // list in RAM.
-            // Building a list of 100k entries that reaches the limit roughly takes
-            // 40 seconds, and roughly corresponds to tenants of 2 TiB physical size.
-            const COMPLEXITY_LIMIT: usize = 100_000;
-            if versions_and_deletes.len() >= COMPLEXITY_LIMIT {
-                return Err(TimeTravelError::TooManyVersions);
-            }
-        }
+            .map_err(|err| match err {
+                DownloadError::Other(e) => TimeTravelError::Other(e),
+                DownloadError::Cancelled => TimeTravelError::Cancelled,
+                other => TimeTravelError::Other(other.into()),
+            })?;
+        let versions_and_deletes = version_listing.versions;
 
         tracing::info!(
             "Built list for time travel with {} versions and deletions",
@@ -948,24 +1012,26 @@ impl RemoteStorage for S3Bucket {
         let mut vds_for_key = HashMap::<_, Vec<_>>::new();
 
         for vd in &versions_and_deletes {
-            let VerOrDelete {
-                version_id, key, ..
-            } = &vd;
-            if version_id == "null" {
+            let Version { key, .. } = &vd;
+            let version_id = vd.version_id().map(|v| v.0.as_str());
+            if version_id == Some("null") {
                 return Err(TimeTravelError::Other(anyhow!(
                     "Received ListVersions response for key={key} with version_id='null', \
                     indicating either disabled versioning, or legacy objects with null version id values"
                 )));
             }
-            tracing::trace!(
-                "Parsing version key={key} version_id={version_id} kind={:?}",
-                vd.kind
-            );
+            tracing::trace!("Parsing version key={key} kind={:?}", vd.kind);
 
             vds_for_key.entry(key).or_default().push(vd);
         }
+
+        let warn_threshold = 3;
+        let max_retries = 10;
+        let is_permanent = |e: &_| matches!(e, TimeTravelError::Cancelled);
+
         for (key, versions) in vds_for_key {
             let last_vd = versions.last().unwrap();
+            let key = self.relative_path_to_s3_object(key);
             if last_vd.last_modified > done_if_after {
                 tracing::trace!("Key {key} has version later than done_if_after, skipping");
                 continue;
@@ -990,11 +1056,11 @@ impl RemoteStorage for S3Bucket {
                 do_delete = true;
             } else {
                 match &versions[version_to_restore_to - 1] {
-                    VerOrDelete {
-                        kind: VerOrDeleteKind::Version,
-                        version_id,
+                    Version {
+                        kind: VersionKind::Version(version_id),
                         ..
                     } => {
+                        let version_id = &version_id.0;
                         tracing::trace!("Copying old version {version_id} for {key}...");
                         // Restore the state to the last version by copying
                         let source_id =
@@ -1006,7 +1072,7 @@ impl RemoteStorage for S3Bucket {
                                     .client
                                     .copy_object()
                                     .bucket(self.bucket_name.clone())
-                                    .key(key)
+                                    .key(&key)
                                     .set_storage_class(self.upload_storage_class.clone())
                                     .copy_source(&source_id)
                                     .send();
@@ -1027,8 +1093,8 @@ impl RemoteStorage for S3Bucket {
                         .and_then(|x| x)?;
                         tracing::info!(%version_id, %key, "Copied old version in S3");
                     }
-                    VerOrDelete {
-                        kind: VerOrDeleteKind::DeleteMarker,
+                    Version {
+                        kind: VersionKind::DeletionMarker,
                         ..
                     } => {
                         do_delete = true;
@@ -1036,7 +1102,7 @@ impl RemoteStorage for S3Bucket {
                 }
             };
             if do_delete {
-                if matches!(last_vd.kind, VerOrDeleteKind::DeleteMarker) {
+                if matches!(last_vd.kind, VersionKind::DeletionMarker) {
                     // Key has since been deleted (but there was some history), no need to do anything
                     tracing::trace!("Key {key} already deleted, skipping.");
                 } else {
@@ -1064,62 +1130,6 @@ impl RemoteStorage for S3Bucket {
     }
 }
 
-// Save RAM and only store the needed data instead of the entire ObjectVersion/DeleteMarkerEntry
-struct VerOrDelete {
-    kind: VerOrDeleteKind,
-    last_modified: DateTime,
-    version_id: String,
-    key: String,
-}
-
-#[derive(Debug)]
-enum VerOrDeleteKind {
-    Version,
-    DeleteMarker,
-}
-
-impl VerOrDelete {
-    fn with_kind(
-        kind: VerOrDeleteKind,
-        last_modified: Option<DateTime>,
-        version_id: Option<String>,
-        key: Option<String>,
-    ) -> anyhow::Result<Self> {
-        let lvk = (last_modified, version_id, key);
-        let (Some(last_modified), Some(version_id), Some(key)) = lvk else {
-            anyhow::bail!(
-                "One (or more) of last_modified, key, and id is None. \
-            Is versioning enabled in the bucket? last_modified={:?}, version_id={:?}, key={:?}",
-                lvk.0,
-                lvk.1,
-                lvk.2,
-            );
-        };
-        Ok(Self {
-            kind,
-            last_modified,
-            version_id,
-            key,
-        })
-    }
-    fn from_version(v: ObjectVersion) -> anyhow::Result<Self> {
-        Self::with_kind(
-            VerOrDeleteKind::Version,
-            v.last_modified,
-            v.version_id,
-            v.key,
-        )
-    }
-    fn from_delete_marker(v: DeleteMarkerEntry) -> anyhow::Result<Self> {
-        Self::with_kind(
-            VerOrDeleteKind::DeleteMarker,
-            v.last_modified,
-            v.version_id,
-            v.key,
-        )
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::num::NonZeroUsize;
diff --git a/libs/remote_storage/src/simulate_failures.rs b/libs/remote_storage/src/simulate_failures.rs
index f56be873c4..894cf600be 100644
--- a/libs/remote_storage/src/simulate_failures.rs
+++ b/libs/remote_storage/src/simulate_failures.rs
@@ -139,6 +139,20 @@ impl RemoteStorage for UnreliableWrapper {
         self.inner.list(prefix, mode, max_keys, cancel).await
     }
 
+    async fn list_versions(
+        &self,
+        prefix: Option<&RemotePath>,
+        mode: ListingMode,
+        max_keys: Option<NonZeroU32>,
+        cancel: &CancellationToken,
+    ) -> Result<crate::VersionListing, DownloadError> {
+        self.attempt(RemoteOp::ListPrefixes(prefix.cloned()))
+            .map_err(DownloadError::Other)?;
+        self.inner
+            .list_versions(prefix, mode, max_keys, cancel)
+            .await
+    }
+
     async fn head_object(
         &self,
         key: &RemotePath,
diff --git a/pageserver/Cargo.toml b/pageserver/Cargo.toml
index fee78aa94d..8abd504922 100644
--- a/pageserver/Cargo.toml
+++ b/pageserver/Cargo.toml
@@ -106,6 +106,7 @@ hex-literal.workspace = true
 tokio = { workspace = true, features = ["process", "sync", "fs", "rt", "io-util", "time", "test-util"] }
 indoc.workspace = true
 uuid.workspace = true
+rstest.workspace = true
 
 [[bench]]
 name = "bench_layer_map"
diff --git a/pageserver/benches/bench_ingest.rs b/pageserver/benches/bench_ingest.rs
index 3108b5351f..2836450a0e 100644
--- a/pageserver/benches/bench_ingest.rs
+++ b/pageserver/benches/bench_ingest.rs
@@ -11,6 +11,7 @@ use pageserver::task_mgr::TaskKind;
 use pageserver::tenant::storage_layer::InMemoryLayer;
 use pageserver::{page_cache, virtual_file};
 use pageserver_api::key::Key;
+use pageserver_api::models::virtual_file::IoMode;
 use pageserver_api::shard::TenantShardId;
 use pageserver_api::value::Value;
 use tokio_util::sync::CancellationToken;
@@ -28,6 +29,7 @@ fn murmurhash32(mut h: u32) -> u32 {
     h
 }
 
+#[derive(serde::Serialize, Clone, Copy, Debug)]
 enum KeyLayout {
     /// Sequential unique keys
     Sequential,
@@ -37,6 +39,7 @@ enum KeyLayout {
     RandomReuse(u32),
 }
 
+#[derive(serde::Serialize, Clone, Copy, Debug)]
 enum WriteDelta {
     Yes,
     No,
@@ -138,12 +141,15 @@ async fn ingest(
 /// Wrapper to instantiate a tokio runtime
 fn ingest_main(
     conf: &'static PageServerConf,
+    io_mode: IoMode,
     put_size: usize,
     put_count: usize,
     key_layout: KeyLayout,
     write_delta: WriteDelta,
 ) {
-    let runtime = tokio::runtime::Builder::new_current_thread()
+    pageserver::virtual_file::set_io_mode(io_mode);
+
+    let runtime = tokio::runtime::Builder::new_multi_thread()
         .enable_all()
         .build()
         .unwrap();
@@ -174,93 +180,245 @@ fn criterion_benchmark(c: &mut Criterion) {
     virtual_file::init(
         16384,
         virtual_file::io_engine_for_bench(),
+        // immaterial, each `ingest_main` invocation below overrides this
         conf.virtual_file_io_mode,
+        // without actually doing syncs, buffered writes have an unfair advantage over direct IO writes
         virtual_file::SyncMode::Sync,
     );
     page_cache::init(conf.page_cache_size);
 
-    {
-        let mut group = c.benchmark_group("ingest-small-values");
-        let put_size = 100usize;
-        let put_count = 128 * 1024 * 1024 / put_size;
-        group.throughput(criterion::Throughput::Bytes((put_size * put_count) as u64));
-        group.sample_size(10);
-        group.bench_function("ingest 128MB/100b seq", |b| {
-            b.iter(|| {
-                ingest_main(
-                    conf,
-                    put_size,
-                    put_count,
-                    KeyLayout::Sequential,
-                    WriteDelta::Yes,
-                )
-            })
-        });
-        group.bench_function("ingest 128MB/100b rand", |b| {
-            b.iter(|| {
-                ingest_main(
-                    conf,
-                    put_size,
-                    put_count,
-                    KeyLayout::Random,
-                    WriteDelta::Yes,
-                )
-            })
-        });
-        group.bench_function("ingest 128MB/100b rand-1024keys", |b| {
-            b.iter(|| {
-                ingest_main(
-                    conf,
-                    put_size,
-                    put_count,
-                    KeyLayout::RandomReuse(0x3ff),
-                    WriteDelta::Yes,
-                )
-            })
-        });
-        group.bench_function("ingest 128MB/100b seq, no delta", |b| {
-            b.iter(|| {
-                ingest_main(
-                    conf,
-                    put_size,
-                    put_count,
-                    KeyLayout::Sequential,
-                    WriteDelta::No,
-                )
-            })
-        });
+    #[derive(serde::Serialize)]
+    struct ExplodedParameters {
+        io_mode: IoMode,
+        volume_mib: usize,
+        key_size: usize,
+        key_layout: KeyLayout,
+        write_delta: WriteDelta,
     }
-
-    {
-        let mut group = c.benchmark_group("ingest-big-values");
-        let put_size = 8192usize;
-        let put_count = 128 * 1024 * 1024 / put_size;
-        group.throughput(criterion::Throughput::Bytes((put_size * put_count) as u64));
+    #[derive(Clone)]
+    struct HandPickedParameters {
+        volume_mib: usize,
+        key_size: usize,
+        key_layout: KeyLayout,
+        write_delta: WriteDelta,
+    }
+    let expect = vec![
+        // Small values (100b) tests
+        HandPickedParameters {
+            volume_mib: 128,
+            key_size: 100,
+            key_layout: KeyLayout::Sequential,
+            write_delta: WriteDelta::Yes,
+        },
+        HandPickedParameters {
+            volume_mib: 128,
+            key_size: 100,
+            key_layout: KeyLayout::Random,
+            write_delta: WriteDelta::Yes,
+        },
+        HandPickedParameters {
+            volume_mib: 128,
+            key_size: 100,
+            key_layout: KeyLayout::RandomReuse(0x3ff),
+            write_delta: WriteDelta::Yes,
+        },
+        HandPickedParameters {
+            volume_mib: 128,
+            key_size: 100,
+            key_layout: KeyLayout::Sequential,
+            write_delta: WriteDelta::No,
+        },
+        // Large values (8k) tests
+        HandPickedParameters {
+            volume_mib: 128,
+            key_size: 8192,
+            key_layout: KeyLayout::Sequential,
+            write_delta: WriteDelta::Yes,
+        },
+        HandPickedParameters {
+            volume_mib: 128,
+            key_size: 8192,
+            key_layout: KeyLayout::Sequential,
+            write_delta: WriteDelta::No,
+        },
+    ];
+    let exploded_parameters = {
+        let mut out = Vec::new();
+        for io_mode in [
+            IoMode::Buffered,
+            #[cfg(target_os = "linux")]
+            IoMode::Direct,
+            #[cfg(target_os = "linux")]
+            IoMode::DirectRw,
+        ] {
+            for param in expect.clone() {
+                let HandPickedParameters {
+                    volume_mib,
+                    key_size,
+                    key_layout,
+                    write_delta,
+                } = param;
+                out.push(ExplodedParameters {
+                    io_mode,
+                    volume_mib,
+                    key_size,
+                    key_layout,
+                    write_delta,
+                });
+            }
+        }
+        out
+    };
+    impl ExplodedParameters {
+        fn benchmark_id(&self) -> String {
+            let ExplodedParameters {
+                io_mode,
+                volume_mib,
+                key_size,
+                key_layout,
+                write_delta,
+            } = self;
+            format!(
+                "io_mode={io_mode:?} volume_mib={volume_mib:?} key_size_bytes={key_size:?} key_layout={key_layout:?} write_delta={write_delta:?}"
+            )
+        }
+    }
+    let mut group = c.benchmark_group("ingest");
+    for params in exploded_parameters {
+        let id = params.benchmark_id();
+        let ExplodedParameters {
+            io_mode,
+            volume_mib,
+            key_size,
+            key_layout,
+            write_delta,
+        } = params;
+        let put_count = volume_mib * 1024 * 1024 / key_size;
+        group.throughput(criterion::Throughput::Bytes((key_size * put_count) as u64));
         group.sample_size(10);
-        group.bench_function("ingest 128MB/8k seq", |b| {
-            b.iter(|| {
-                ingest_main(
-                    conf,
-                    put_size,
-                    put_count,
-                    KeyLayout::Sequential,
-                    WriteDelta::Yes,
-                )
-            })
-        });
-        group.bench_function("ingest 128MB/8k seq, no delta", |b| {
-            b.iter(|| {
-                ingest_main(
-                    conf,
-                    put_size,
-                    put_count,
-                    KeyLayout::Sequential,
-                    WriteDelta::No,
-                )
-            })
+        group.bench_function(id, |b| {
+            b.iter(|| ingest_main(conf, io_mode, key_size, put_count, key_layout, write_delta))
         });
     }
 }
 
 criterion_group!(benches, criterion_benchmark);
 criterion_main!(benches);
+
+/*
+cargo bench --bench bench_ingest
+
+im4gn.2xlarge:
+
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=Yes
+                        time:   [1.2901 s 1.2943 s 1.2991 s]
+                        thrpt:  [98.533 MiB/s 98.892 MiB/s 99.220 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=Random write_delta=Yes
+                        time:   [2.1387 s 2.1623 s 2.1845 s]
+                        thrpt:  [58.595 MiB/s 59.197 MiB/s 59.851 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=RandomReuse(1023) write_delta=Y...
+                        time:   [1.2036 s 1.2074 s 1.2122 s]
+                        thrpt:  [105.60 MiB/s 106.01 MiB/s 106.35 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=No
+                        time:   [520.55 ms 521.46 ms 522.57 ms]
+                        thrpt:  [244.94 MiB/s 245.47 MiB/s 245.89 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=Yes
+                        time:   [440.33 ms 442.24 ms 444.10 ms]
+                        thrpt:  [288.22 MiB/s 289.43 MiB/s 290.69 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=No
+                        time:   [168.78 ms 169.42 ms 170.18 ms]
+                        thrpt:  [752.16 MiB/s 755.52 MiB/s 758.40 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=Yes
+                        time:   [1.2978 s 1.3094 s 1.3227 s]
+                        thrpt:  [96.775 MiB/s 97.758 MiB/s 98.632 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=Random write_delta=Yes
+                        time:   [2.1976 s 2.2067 s 2.2154 s]
+                        thrpt:  [57.777 MiB/s 58.006 MiB/s 58.245 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=RandomReuse(1023) write_delta=Yes
+                        time:   [1.2103 s 1.2160 s 1.2233 s]
+                        thrpt:  [104.64 MiB/s 105.26 MiB/s 105.76 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=No
+                        time:   [525.05 ms 526.37 ms 527.79 ms]
+                        thrpt:  [242.52 MiB/s 243.17 MiB/s 243.79 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=Yes
+                        time:   [443.06 ms 444.88 ms 447.15 ms]
+                        thrpt:  [286.26 MiB/s 287.72 MiB/s 288.90 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=No
+                        time:   [169.40 ms 169.80 ms 170.17 ms]
+                        thrpt:  [752.21 MiB/s 753.81 MiB/s 755.60 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=Yes
+                        time:   [1.2844 s 1.2915 s 1.2990 s]
+                        thrpt:  [98.536 MiB/s 99.112 MiB/s 99.657 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=Random write_delta=Yes
+                        time:   [2.1431 s 2.1663 s 2.1900 s]
+                        thrpt:  [58.446 MiB/s 59.087 MiB/s 59.726 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=RandomReuse(1023) write_delta=Y...
+                        time:   [1.1906 s 1.1926 s 1.1947 s]
+                        thrpt:  [107.14 MiB/s 107.33 MiB/s 107.51 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=No
+                        time:   [516.86 ms 518.25 ms 519.47 ms]
+                        thrpt:  [246.40 MiB/s 246.98 MiB/s 247.65 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=Yes
+                        time:   [536.50 ms 536.53 ms 536.60 ms]
+                        thrpt:  [238.54 MiB/s 238.57 MiB/s 238.59 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=No
+                        time:   [267.77 ms 267.90 ms 268.04 ms]
+                        thrpt:  [477.53 MiB/s 477.79 MiB/s 478.02 MiB/s]
+
+Hetzner AX102:
+
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=Yes
+                        time:   [836.58 ms 861.93 ms 886.57 ms]
+                        thrpt:  [144.38 MiB/s 148.50 MiB/s 153.00 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=Random write_delta=Yes
+                        time:   [1.2782 s 1.3191 s 1.3665 s]
+                        thrpt:  [93.668 MiB/s 97.037 MiB/s 100.14 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=RandomReuse(1023) write_delta=Y...
+                        time:   [791.27 ms 807.08 ms 822.95 ms]
+                        thrpt:  [155.54 MiB/s 158.60 MiB/s 161.77 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=No
+                        time:   [310.78 ms 314.66 ms 318.47 ms]
+                        thrpt:  [401.92 MiB/s 406.79 MiB/s 411.87 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=Yes
+                        time:   [377.11 ms 387.77 ms 399.21 ms]
+                        thrpt:  [320.63 MiB/s 330.10 MiB/s 339.42 MiB/s]
+ingest/io_mode=Buffered volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=No
+                        time:   [128.37 ms 132.96 ms 138.55 ms]
+                        thrpt:  [923.83 MiB/s 962.69 MiB/s 997.11 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=Yes
+                        time:   [900.38 ms 914.88 ms 928.86 ms]
+                        thrpt:  [137.80 MiB/s 139.91 MiB/s 142.16 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=Random write_delta=Yes
+                        time:   [1.2538 s 1.2936 s 1.3313 s]
+                        thrpt:  [96.149 MiB/s 98.946 MiB/s 102.09 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=RandomReuse(1023) write_delta=Yes
+                        time:   [787.17 ms 803.89 ms 820.63 ms]
+                        thrpt:  [155.98 MiB/s 159.23 MiB/s 162.61 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=No
+                        time:   [318.78 ms 321.89 ms 324.74 ms]
+                        thrpt:  [394.16 MiB/s 397.65 MiB/s 401.53 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=Yes
+                        time:   [374.01 ms 383.45 ms 393.20 ms]
+                        thrpt:  [325.53 MiB/s 333.81 MiB/s 342.24 MiB/s]
+ingest/io_mode=Direct volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=No
+                        time:   [137.98 ms 141.31 ms 143.57 ms]
+                        thrpt:  [891.58 MiB/s 905.79 MiB/s 927.66 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=Yes
+                        time:   [613.69 ms 622.48 ms 630.97 ms]
+                        thrpt:  [202.86 MiB/s 205.63 MiB/s 208.57 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=Random write_delta=Yes
+                        time:   [1.0299 s 1.0766 s 1.1273 s]
+                        thrpt:  [113.55 MiB/s 118.90 MiB/s 124.29 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=RandomReuse(1023) write_delta=Y...
+                        time:   [637.80 ms 647.78 ms 658.01 ms]
+                        thrpt:  [194.53 MiB/s 197.60 MiB/s 200.69 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=100 key_layout=Sequential write_delta=No
+                        time:   [266.09 ms 267.20 ms 268.31 ms]
+                        thrpt:  [477.06 MiB/s 479.04 MiB/s 481.04 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=Yes
+                        time:   [269.34 ms 273.27 ms 277.69 ms]
+                        thrpt:  [460.95 MiB/s 468.40 MiB/s 475.24 MiB/s]
+ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=8192 key_layout=Sequential write_delta=No
+                        time:   [123.18 ms 124.24 ms 125.15 ms]
+                        thrpt:  [1022.8 MiB/s 1.0061 GiB/s 1.0148 GiB/s]
+*/
diff --git a/pageserver/client/src/mgmt_api.rs b/pageserver/client/src/mgmt_api.rs
index e0cd19817d..4a87a91910 100644
--- a/pageserver/client/src/mgmt_api.rs
+++ b/pageserver/client/src/mgmt_api.rs
@@ -419,6 +419,23 @@ impl Client {
         }
     }
 
+    pub async fn timeline_detail(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+    ) -> Result<TimelineInfo> {
+        let uri = format!(
+            "{}/v1/tenant/{tenant_shard_id}/timeline/{timeline_id}",
+            self.mgmt_api_endpoint
+        );
+
+        self.request(Method::GET, &uri, ())
+            .await?
+            .json()
+            .await
+            .map_err(Error::ReceiveBody)
+    }
+
     pub async fn timeline_archival_config(
         &self,
         tenant_shard_id: TenantShardId,
diff --git a/pageserver/src/config.rs b/pageserver/src/config.rs
index d4bfed95a1..95143e58b7 100644
--- a/pageserver/src/config.rs
+++ b/pageserver/src/config.rs
@@ -225,6 +225,11 @@ pub struct PageServerConf {
     /// Does not force TLS: the client negotiates TLS usage during the handshake.
     /// Uses key and certificate from ssl_key_file/ssl_cert_file.
     pub enable_tls_page_service_api: bool,
+
+    /// Run in development mode, which disables certain safety checks
+    /// such as authentication requirements for HTTP and PostgreSQL APIs.
+    /// This is insecure and should only be used in development environments.
+    pub dev_mode: bool,
 }
 
 /// Token for authentication to safekeepers
@@ -398,6 +403,7 @@ impl PageServerConf {
             generate_unarchival_heatmap,
             tracing,
             enable_tls_page_service_api,
+            dev_mode,
         } = config_toml;
 
         let mut conf = PageServerConf {
@@ -449,6 +455,7 @@ impl PageServerConf {
             get_vectored_concurrent_io,
             tracing,
             enable_tls_page_service_api,
+            dev_mode,
 
             // ------------------------------------------------------------
             // fields that require additional validation or custom handling
diff --git a/pageserver/src/controller_upcall_client.rs b/pageserver/src/controller_upcall_client.rs
index ed52823c20..59c94f1549 100644
--- a/pageserver/src/controller_upcall_client.rs
+++ b/pageserver/src/controller_upcall_client.rs
@@ -3,10 +3,11 @@ use std::collections::HashMap;
 use futures::Future;
 use pageserver_api::config::NodeMetadata;
 use pageserver_api::controller_api::{AvailabilityZone, NodeRegisterRequest};
+use pageserver_api::models::ShardImportStatus;
 use pageserver_api::shard::TenantShardId;
 use pageserver_api::upcall_api::{
-    ReAttachRequest, ReAttachResponse, ReAttachResponseTenant, ValidateRequest,
-    ValidateRequestTenant, ValidateResponse,
+    PutTimelineImportStatusRequest, ReAttachRequest, ReAttachResponse, ReAttachResponseTenant,
+    ValidateRequest, ValidateRequestTenant, ValidateResponse,
 };
 use reqwest::Certificate;
 use serde::Serialize;
@@ -14,7 +15,7 @@ use serde::de::DeserializeOwned;
 use tokio_util::sync::CancellationToken;
 use url::Url;
 use utils::generation::Generation;
-use utils::id::NodeId;
+use utils::id::{NodeId, TimelineId};
 use utils::{backoff, failpoint_support};
 
 use crate::config::PageServerConf;
@@ -46,6 +47,12 @@ pub trait StorageControllerUpcallApi {
         &self,
         tenants: Vec<(TenantShardId, Generation)>,
     ) -> impl Future<Output = Result<HashMap<TenantShardId, bool>, RetryForeverError>> + Send;
+    fn put_timeline_import_status(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+        status: ShardImportStatus,
+    ) -> impl Future<Output = Result<(), RetryForeverError>> + Send;
 }
 
 impl StorageControllerUpcallClient {
@@ -273,4 +280,30 @@ impl StorageControllerUpcallApi for StorageControllerUpcallClient {
 
         Ok(result.into_iter().collect())
     }
+
+    /// Send a shard import status to the storage controller
+    ///
+    /// The implementation must have at-least-once delivery semantics.
+    /// To this end, we retry the request until it succeeds. If the pageserver
+    /// restarts or crashes, the shard import will start again from the beggining.
+    #[tracing::instrument(skip_all)] // so that warning logs from retry_http_forever have context
+    async fn put_timeline_import_status(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+        status: ShardImportStatus,
+    ) -> Result<(), RetryForeverError> {
+        let url = self
+            .base_url
+            .join("timeline_import_status")
+            .expect("Failed to build path");
+
+        let request = PutTimelineImportStatusRequest {
+            tenant_shard_id,
+            timeline_id,
+            status,
+        };
+
+        self.retry_http_forever(&url, request).await
+    }
 }
diff --git a/pageserver/src/deletion_queue.rs b/pageserver/src/deletion_queue.rs
index d9c1c07b10..6dd7d741c1 100644
--- a/pageserver/src/deletion_queue.rs
+++ b/pageserver/src/deletion_queue.rs
@@ -787,6 +787,15 @@ mod test {
 
             Ok(result)
         }
+
+        async fn put_timeline_import_status(
+            &self,
+            _tenant_shard_id: TenantShardId,
+            _timeline_id: TimelineId,
+            _status: pageserver_api::models::ShardImportStatus,
+        ) -> Result<(), RetryForeverError> {
+            unimplemented!()
+        }
     }
 
     async fn setup(test_name: &str) -> anyhow::Result<TestSetup> {
diff --git a/pageserver/src/metrics.rs b/pageserver/src/metrics.rs
index ce229bbbec..b16970c911 100644
--- a/pageserver/src/metrics.rs
+++ b/pageserver/src/metrics.rs
@@ -1289,6 +1289,7 @@ pub(crate) enum StorageIoOperation {
     Seek,
     Fsync,
     Metadata,
+    SetLen,
 }
 
 impl StorageIoOperation {
@@ -1303,6 +1304,7 @@ impl StorageIoOperation {
             StorageIoOperation::Seek => "seek",
             StorageIoOperation::Fsync => "fsync",
             StorageIoOperation::Metadata => "metadata",
+            StorageIoOperation::SetLen => "set_len",
         }
     }
 }
diff --git a/pageserver/src/tenant/blob_io.rs b/pageserver/src/tenant/blob_io.rs
index 3483a9f31e..8cf3c548c9 100644
--- a/pageserver/src/tenant/blob_io.rs
+++ b/pageserver/src/tenant/blob_io.rs
@@ -15,21 +15,23 @@
 //! len >= 128: 1CCCXXXX XXXXXXXX XXXXXXXX XXXXXXXX
 //!
 use std::cmp::min;
-use std::io::Error;
 
+use anyhow::Context;
 use async_compression::Level;
 use bytes::{BufMut, BytesMut};
 use pageserver_api::models::ImageCompressionAlgorithm;
 use tokio::io::AsyncWriteExt;
-use tokio_epoll_uring::{BoundedBuf, IoBuf, Slice};
+use tokio_epoll_uring::IoBuf;
 use tokio_util::sync::CancellationToken;
 use tracing::warn;
 
 use crate::context::RequestContext;
 use crate::page_cache::PAGE_SZ;
 use crate::tenant::block_io::BlockCursor;
-use crate::virtual_file::VirtualFile;
+use crate::virtual_file::IoBufferMut;
 use crate::virtual_file::owned_buffers_io::io_buf_ext::{FullSlice, IoBufExt};
+use crate::virtual_file::owned_buffers_io::write::{BufferedWriter, FlushTaskError};
+use crate::virtual_file::owned_buffers_io::write::{BufferedWriterShutdownMode, OwnedAsyncWriter};
 
 #[derive(Copy, Clone, Debug)]
 pub struct CompressionInfo {
@@ -50,12 +52,9 @@ pub struct Header {
 
 impl Header {
     /// Decodes a header from a byte slice.
-    pub fn decode(bytes: &[u8]) -> Result<Self, std::io::Error> {
+    pub fn decode(bytes: &[u8]) -> anyhow::Result<Self> {
         let Some(&first_header_byte) = bytes.first() else {
-            return Err(std::io::Error::new(
-                std::io::ErrorKind::InvalidData,
-                "zero-length blob header",
-            ));
+            anyhow::bail!("zero-length blob header");
         };
 
         // If the first bit is 0, this is just a 1-byte length prefix up to 128 bytes.
@@ -69,12 +68,9 @@ impl Header {
 
         // Otherwise, this is a 4-byte header containing compression information and length.
         const HEADER_LEN: usize = 4;
-        let mut header_buf: [u8; HEADER_LEN] = bytes[0..HEADER_LEN].try_into().map_err(|_| {
-            std::io::Error::new(
-                std::io::ErrorKind::InvalidData,
-                format!("blob header too short: {bytes:?}"),
-            )
-        })?;
+        let mut header_buf: [u8; HEADER_LEN] = bytes[0..HEADER_LEN]
+            .try_into()
+            .map_err(|_| anyhow::anyhow!("blob header too short: {bytes:?}"))?;
 
         // TODO: verify the compression bits and convert to an enum.
         let compression_bits = header_buf[0] & LEN_COMPRESSION_BIT_MASK;
@@ -94,6 +90,16 @@ impl Header {
     }
 }
 
+#[derive(Debug, thiserror::Error)]
+pub enum WriteBlobError {
+    #[error(transparent)]
+    Flush(FlushTaskError),
+    #[error("blob too large ({len} bytes)")]
+    BlobTooLarge { len: usize },
+    #[error(transparent)]
+    WriteBlobRaw(anyhow::Error),
+}
+
 impl BlockCursor<'_> {
     /// Read a blob into a new buffer.
     pub async fn read_blob(
@@ -213,143 +219,64 @@ pub(super) const BYTE_UNCOMPRESSED: u8 = 0x80;
 pub(super) const BYTE_ZSTD: u8 = BYTE_UNCOMPRESSED | 0x10;
 
 /// A wrapper of `VirtualFile` that allows users to write blobs.
-///
-/// If a `BlobWriter` is dropped, the internal buffer will be
-/// discarded. You need to call [`flush_buffer`](Self::flush_buffer)
-/// manually before dropping.
-pub struct BlobWriter<const BUFFERED: bool> {
-    inner: VirtualFile,
-    offset: u64,
-    /// A buffer to save on write calls, only used if BUFFERED=true
-    buf: Vec<u8>,
+pub struct BlobWriter<W> {
     /// We do tiny writes for the length headers; they need to be in an owned buffer;
     io_buf: Option<BytesMut>,
+    writer: BufferedWriter<IoBufferMut, W>,
+    offset: u64,
 }
 
-impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
+impl<W> BlobWriter<W>
+where
+    W: OwnedAsyncWriter + std::fmt::Debug + Send + Sync + 'static,
+{
+    /// See [`BufferedWriter`] struct-level doc comment for semantics of `start_offset`.
     pub fn new(
-        inner: VirtualFile,
+        file: W,
         start_offset: u64,
-        _gate: &utils::sync::gate::Gate,
-        _cancel: CancellationToken,
-        _ctx: &RequestContext,
-    ) -> Self {
-        Self {
-            inner,
-            offset: start_offset,
-            buf: Vec::with_capacity(Self::CAPACITY),
+        gate: &utils::sync::gate::Gate,
+        cancel: CancellationToken,
+        ctx: &RequestContext,
+        flush_task_span: tracing::Span,
+    ) -> anyhow::Result<Self> {
+        Ok(Self {
             io_buf: Some(BytesMut::new()),
-        }
+            writer: BufferedWriter::new(
+                file,
+                start_offset,
+                || IoBufferMut::with_capacity(Self::CAPACITY),
+                gate.enter()?,
+                cancel,
+                ctx,
+                flush_task_span,
+            ),
+            offset: start_offset,
+        })
     }
 
     pub fn size(&self) -> u64 {
         self.offset
     }
 
-    const CAPACITY: usize = if BUFFERED { 64 * 1024 } else { 0 };
+    const CAPACITY: usize = 64 * 1024;
 
-    /// Writes the given buffer directly to the underlying `VirtualFile`.
-    /// You need to make sure that the internal buffer is empty, otherwise
-    /// data will be written in wrong order.
-    #[inline(always)]
-    async fn write_all_unbuffered<Buf: IoBuf + Send>(
-        &mut self,
-        src_buf: FullSlice<Buf>,
-        ctx: &RequestContext,
-    ) -> (FullSlice<Buf>, Result<(), Error>) {
-        let (src_buf, res) = self.inner.write_all(src_buf, ctx).await;
-        let nbytes = match res {
-            Ok(nbytes) => nbytes,
-            Err(e) => return (src_buf, Err(e)),
-        };
-        self.offset += nbytes as u64;
-        (src_buf, Ok(()))
-    }
-
-    #[inline(always)]
-    /// Flushes the internal buffer to the underlying `VirtualFile`.
-    pub async fn flush_buffer(&mut self, ctx: &RequestContext) -> Result<(), Error> {
-        let buf = std::mem::take(&mut self.buf);
-        let (slice, res) = self.inner.write_all(buf.slice_len(), ctx).await;
-        res?;
-        let mut buf = slice.into_raw_slice().into_inner();
-        buf.clear();
-        self.buf = buf;
-        Ok(())
-    }
-
-    #[inline(always)]
-    /// Writes as much of `src_buf` into the internal buffer as it fits
-    fn write_into_buffer(&mut self, src_buf: &[u8]) -> usize {
-        let remaining = Self::CAPACITY - self.buf.len();
-        let to_copy = src_buf.len().min(remaining);
-        self.buf.extend_from_slice(&src_buf[..to_copy]);
-        self.offset += to_copy as u64;
-        to_copy
-    }
-
-    /// Internal, possibly buffered, write function
+    /// Writes `src_buf` to the file at the current offset.
     async fn write_all<Buf: IoBuf + Send>(
         &mut self,
         src_buf: FullSlice<Buf>,
         ctx: &RequestContext,
-    ) -> (FullSlice<Buf>, Result<(), Error>) {
-        let src_buf = src_buf.into_raw_slice();
-        let src_buf_bounds = src_buf.bounds();
-        let restore = move |src_buf_slice: Slice<_>| {
-            FullSlice::must_new(Slice::from_buf_bounds(
-                src_buf_slice.into_inner(),
-                src_buf_bounds,
-            ))
-        };
+    ) -> (FullSlice<Buf>, Result<(), FlushTaskError>) {
+        let res = self
+            .writer
+            // TODO: why are we taking a FullSlice if we're going to pass a borrow downstack?
+            // Can remove all the complexity around owned buffers upstack
+            .write_buffered_borrowed(&src_buf, ctx)
+            .await
+            .map(|len| {
+                self.offset += len as u64;
+            });
 
-        if !BUFFERED {
-            assert!(self.buf.is_empty());
-            return self
-                .write_all_unbuffered(FullSlice::must_new(src_buf), ctx)
-                .await;
-        }
-        let remaining = Self::CAPACITY - self.buf.len();
-        let src_buf_len = src_buf.bytes_init();
-        if src_buf_len == 0 {
-            return (restore(src_buf), Ok(()));
-        }
-        let mut src_buf = src_buf.slice(0..src_buf_len);
-        // First try to copy as much as we can into the buffer
-        if remaining > 0 {
-            let copied = self.write_into_buffer(&src_buf);
-            src_buf = src_buf.slice(copied..);
-        }
-        // Then, if the buffer is full, flush it out
-        if self.buf.len() == Self::CAPACITY {
-            if let Err(e) = self.flush_buffer(ctx).await {
-                return (restore(src_buf), Err(e));
-            }
-        }
-        // Finally, write the tail of src_buf:
-        // If it wholly fits into the buffer without
-        // completely filling it, then put it there.
-        // If not, write it out directly.
-        let src_buf = if !src_buf.is_empty() {
-            assert_eq!(self.buf.len(), 0);
-            if src_buf.len() < Self::CAPACITY {
-                let copied = self.write_into_buffer(&src_buf);
-                // We just verified above that src_buf fits into our internal buffer.
-                assert_eq!(copied, src_buf.len());
-                restore(src_buf)
-            } else {
-                let (src_buf, res) = self
-                    .write_all_unbuffered(FullSlice::must_new(src_buf), ctx)
-                    .await;
-                if let Err(e) = res {
-                    return (src_buf, Err(e));
-                }
-                src_buf
-            }
-        } else {
-            restore(src_buf)
-        };
-        (src_buf, Ok(()))
+        (src_buf, res)
     }
 
     /// Write a blob of data. Returns the offset that it was written to,
@@ -358,7 +285,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
         &mut self,
         srcbuf: FullSlice<Buf>,
         ctx: &RequestContext,
-    ) -> (FullSlice<Buf>, Result<u64, Error>) {
+    ) -> (FullSlice<Buf>, Result<u64, WriteBlobError>) {
         let (buf, res) = self
             .write_blob_maybe_compressed(srcbuf, ctx, ImageCompressionAlgorithm::Disabled)
             .await;
@@ -372,7 +299,10 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
         srcbuf: FullSlice<Buf>,
         ctx: &RequestContext,
         algorithm: ImageCompressionAlgorithm,
-    ) -> (FullSlice<Buf>, Result<(u64, CompressionInfo), Error>) {
+    ) -> (
+        FullSlice<Buf>,
+        Result<(u64, CompressionInfo), WriteBlobError>,
+    ) {
         let offset = self.offset;
         let mut compression_info = CompressionInfo {
             written_compressed: false,
@@ -388,14 +318,16 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
             if len < 128 {
                 // Short blob. Write a 1-byte length header
                 io_buf.put_u8(len as u8);
-                (self.write_all(io_buf.slice_len(), ctx).await, srcbuf)
+                let (slice, res) = self.write_all(io_buf.slice_len(), ctx).await;
+                let res = res.map_err(WriteBlobError::Flush);
+                ((slice, res), srcbuf)
             } else {
                 // Write a 4-byte length header
                 if len > MAX_SUPPORTED_BLOB_LEN {
                     return (
                         (
                             io_buf.slice_len(),
-                            Err(Error::other(format!("blob too large ({len} bytes)"))),
+                            Err(WriteBlobError::BlobTooLarge { len }),
                         ),
                         srcbuf,
                     );
@@ -429,7 +361,9 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
                 assert_eq!(len_buf[0] & 0xf0, 0);
                 len_buf[0] |= high_bit_mask;
                 io_buf.extend_from_slice(&len_buf[..]);
-                (self.write_all(io_buf.slice_len(), ctx).await, srcbuf)
+                let (slice, res) = self.write_all(io_buf.slice_len(), ctx).await;
+                let res = res.map_err(WriteBlobError::Flush);
+                ((slice, res), srcbuf)
             }
         }
         .await;
@@ -444,6 +378,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
         } else {
             self.write_all(srcbuf, ctx).await
         };
+        let res = res.map_err(WriteBlobError::Flush);
         (srcbuf, res.map(|_| (offset, compression_info)))
     }
 
@@ -452,9 +387,12 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
         &mut self,
         raw_with_header: FullSlice<Buf>,
         ctx: &RequestContext,
-    ) -> (FullSlice<Buf>, Result<u64, Error>) {
+    ) -> (FullSlice<Buf>, Result<u64, WriteBlobError>) {
         // Verify the header, to ensure we don't write invalid/corrupt data.
-        let header = match Header::decode(&raw_with_header) {
+        let header = match Header::decode(&raw_with_header)
+            .context("decoding blob header")
+            .map_err(WriteBlobError::WriteBlobRaw)
+        {
             Ok(header) => header,
             Err(err) => return (raw_with_header, Err(err)),
         };
@@ -463,42 +401,26 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
             let raw_len = raw_with_header.len();
             return (
                 raw_with_header,
-                Err(std::io::Error::new(
-                    std::io::ErrorKind::InvalidData,
-                    format!("header length mismatch: {header_total_len} != {raw_len}"),
-                )),
+                Err(WriteBlobError::WriteBlobRaw(anyhow::anyhow!(
+                    "header length mismatch: {header_total_len} != {raw_len}"
+                ))),
             );
         }
 
         let offset = self.offset;
         let (raw_with_header, result) = self.write_all(raw_with_header, ctx).await;
+        let result = result.map_err(WriteBlobError::Flush);
         (raw_with_header, result.map(|_| offset))
     }
-}
 
-impl BlobWriter<true> {
-    /// Access the underlying `VirtualFile`.
-    ///
-    /// This function flushes the internal buffer before giving access
-    /// to the underlying `VirtualFile`.
-    pub async fn into_inner(mut self, ctx: &RequestContext) -> Result<VirtualFile, Error> {
-        self.flush_buffer(ctx).await?;
-        Ok(self.inner)
-    }
-
-    /// Access the underlying `VirtualFile`.
-    ///
-    /// Unlike [`into_inner`](Self::into_inner), this doesn't flush
-    /// the internal buffer before giving access.
-    pub fn into_inner_no_flush(self) -> VirtualFile {
-        self.inner
-    }
-}
-
-impl BlobWriter<false> {
-    /// Access the underlying `VirtualFile`.
-    pub fn into_inner(self) -> VirtualFile {
-        self.inner
+    /// Finish this blob writer and return the underlying `W`.
+    pub async fn shutdown(
+        self,
+        mode: BufferedWriterShutdownMode,
+        ctx: &RequestContext,
+    ) -> Result<W, FlushTaskError> {
+        let (_, file) = self.writer.shutdown(mode, ctx).await?;
+        Ok(file)
     }
 }
 
@@ -507,21 +429,25 @@ pub(crate) mod tests {
     use camino::Utf8PathBuf;
     use camino_tempfile::Utf8TempDir;
     use rand::{Rng, SeedableRng};
+    use tracing::info_span;
 
     use super::*;
     use crate::context::DownloadBehavior;
     use crate::task_mgr::TaskKind;
     use crate::tenant::block_io::BlockReaderRef;
+    use crate::virtual_file;
+    use crate::virtual_file::TempVirtualFile;
+    use crate::virtual_file::VirtualFile;
 
-    async fn round_trip_test<const BUFFERED: bool>(blobs: &[Vec<u8>]) -> Result<(), Error> {
-        round_trip_test_compressed::<BUFFERED>(blobs, false).await
+    async fn round_trip_test(blobs: &[Vec<u8>]) -> anyhow::Result<()> {
+        round_trip_test_compressed(blobs, false).await
     }
 
-    pub(crate) async fn write_maybe_compressed<const BUFFERED: bool>(
+    pub(crate) async fn write_maybe_compressed(
         blobs: &[Vec<u8>],
         compression: bool,
         ctx: &RequestContext,
-    ) -> Result<(Utf8TempDir, Utf8PathBuf, Vec<u64>), Error> {
+    ) -> anyhow::Result<(Utf8TempDir, Utf8PathBuf, Vec<u64>)> {
         let temp_dir = camino_tempfile::tempdir()?;
         let pathbuf = temp_dir.path().join("file");
         let gate = utils::sync::gate::Gate::default();
@@ -530,8 +456,19 @@ pub(crate) mod tests {
         // Write part (in block to drop the file)
         let mut offsets = Vec::new();
         {
-            let file = VirtualFile::create(pathbuf.as_path(), ctx).await?;
-            let mut wtr = BlobWriter::<BUFFERED>::new(file, 0, &gate, cancel.clone(), ctx);
+            let file = TempVirtualFile::new(
+                VirtualFile::open_with_options_v2(
+                    pathbuf.as_path(),
+                    virtual_file::OpenOptions::new()
+                        .create_new(true)
+                        .write(true),
+                    ctx,
+                )
+                .await?,
+                gate.enter()?,
+            );
+            let mut wtr =
+                BlobWriter::new(file, 0, &gate, cancel.clone(), ctx, info_span!("test")).unwrap();
             for blob in blobs.iter() {
                 let (_, res) = if compression {
                     let res = wtr
@@ -548,26 +485,28 @@ pub(crate) mod tests {
                 let offs = res?;
                 offsets.push(offs);
             }
-            // Write out one page worth of zeros so that we can
-            // read again with read_blk
-            let (_, res) = wtr.write_blob(vec![0; PAGE_SZ].slice_len(), ctx).await;
-            let offs = res?;
-            println!("Writing final blob at offs={offs}");
-            wtr.flush_buffer(ctx).await?;
-        }
+            let file = wtr
+                .shutdown(
+                    BufferedWriterShutdownMode::ZeroPadToNextMultiple(PAGE_SZ),
+                    ctx,
+                )
+                .await?;
+            file.disarm_into_inner()
+        };
         Ok((temp_dir, pathbuf, offsets))
     }
 
-    async fn round_trip_test_compressed<const BUFFERED: bool>(
+    async fn round_trip_test_compressed(
         blobs: &[Vec<u8>],
         compression: bool,
-    ) -> Result<(), Error> {
+    ) -> anyhow::Result<()> {
         let ctx =
             RequestContext::new(TaskKind::UnitTest, DownloadBehavior::Error).with_scope_unit_test();
         let (_temp_dir, pathbuf, offsets) =
-            write_maybe_compressed::<BUFFERED>(blobs, compression, &ctx).await?;
+            write_maybe_compressed(blobs, compression, &ctx).await?;
 
-        let file = VirtualFile::open(pathbuf, &ctx).await?;
+        println!("Done writing!");
+        let file = VirtualFile::open_v2(pathbuf, &ctx).await?;
         let rdr = BlockReaderRef::VirtualFile(&file);
         let rdr = BlockCursor::new_with_compression(rdr, compression);
         for (idx, (blob, offset)) in blobs.iter().zip(offsets.iter()).enumerate() {
@@ -586,30 +525,27 @@ pub(crate) mod tests {
     }
 
     #[tokio::test]
-    async fn test_one() -> Result<(), Error> {
+    async fn test_one() -> anyhow::Result<()> {
         let blobs = &[vec![12, 21, 22]];
-        round_trip_test::<false>(blobs).await?;
-        round_trip_test::<true>(blobs).await?;
+        round_trip_test(blobs).await?;
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_hello_simple() -> Result<(), Error> {
+    async fn test_hello_simple() -> anyhow::Result<()> {
         let blobs = &[
             vec![0, 1, 2, 3],
             b"Hello, World!".to_vec(),
             Vec::new(),
             b"foobar".to_vec(),
         ];
-        round_trip_test::<false>(blobs).await?;
-        round_trip_test::<true>(blobs).await?;
-        round_trip_test_compressed::<false>(blobs, true).await?;
-        round_trip_test_compressed::<true>(blobs, true).await?;
+        round_trip_test(blobs).await?;
+        round_trip_test_compressed(blobs, true).await?;
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_really_big_array() -> Result<(), Error> {
+    async fn test_really_big_array() -> anyhow::Result<()> {
         let blobs = &[
             b"test".to_vec(),
             random_array(10 * PAGE_SZ),
@@ -618,25 +554,22 @@ pub(crate) mod tests {
             vec![0xf3; 24 * PAGE_SZ],
             b"foobar".to_vec(),
         ];
-        round_trip_test::<false>(blobs).await?;
-        round_trip_test::<true>(blobs).await?;
-        round_trip_test_compressed::<false>(blobs, true).await?;
-        round_trip_test_compressed::<true>(blobs, true).await?;
+        round_trip_test(blobs).await?;
+        round_trip_test_compressed(blobs, true).await?;
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_arrays_inc() -> Result<(), Error> {
+    async fn test_arrays_inc() -> anyhow::Result<()> {
         let blobs = (0..PAGE_SZ / 8)
             .map(|v| random_array(v * 16))
             .collect::<Vec<_>>();
-        round_trip_test::<false>(&blobs).await?;
-        round_trip_test::<true>(&blobs).await?;
+        round_trip_test(&blobs).await?;
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_arrays_random_size() -> Result<(), Error> {
+    async fn test_arrays_random_size() -> anyhow::Result<()> {
         let mut rng = rand::rngs::StdRng::seed_from_u64(42);
         let blobs = (0..1024)
             .map(|_| {
@@ -648,20 +581,18 @@ pub(crate) mod tests {
                 random_array(sz.into())
             })
             .collect::<Vec<_>>();
-        round_trip_test::<false>(&blobs).await?;
-        round_trip_test::<true>(&blobs).await?;
+        round_trip_test(&blobs).await?;
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_arrays_page_boundary() -> Result<(), Error> {
+    async fn test_arrays_page_boundary() -> anyhow::Result<()> {
         let blobs = &[
             random_array(PAGE_SZ - 4),
             random_array(PAGE_SZ - 4),
             random_array(PAGE_SZ - 4),
         ];
-        round_trip_test::<false>(blobs).await?;
-        round_trip_test::<true>(blobs).await?;
+        round_trip_test(blobs).await?;
         Ok(())
     }
 }
diff --git a/pageserver/src/tenant/block_io.rs b/pageserver/src/tenant/block_io.rs
index 6723155626..686cc94126 100644
--- a/pageserver/src/tenant/block_io.rs
+++ b/pageserver/src/tenant/block_io.rs
@@ -4,14 +4,12 @@
 
 use std::ops::Deref;
 
-use bytes::Bytes;
-
 use super::storage_layer::delta_layer::{Adapter, DeltaLayerInner};
 use crate::context::RequestContext;
 use crate::page_cache::{self, FileId, PAGE_SZ, PageReadGuard, PageWriteGuard, ReadBufResult};
 #[cfg(test)]
 use crate::virtual_file::IoBufferMut;
-use crate::virtual_file::VirtualFile;
+use crate::virtual_file::{IoBuffer, VirtualFile};
 
 /// This is implemented by anything that can read 8 kB (PAGE_SZ)
 /// blocks, using the page cache
@@ -247,17 +245,17 @@ pub trait BlockWriter {
     /// 'buf' must be of size PAGE_SZ. Returns the block number the page was
     /// written to.
     ///
-    fn write_blk(&mut self, buf: Bytes) -> Result<u32, std::io::Error>;
+    fn write_blk(&mut self, buf: IoBuffer) -> Result<u32, std::io::Error>;
 }
 
 ///
 /// A simple in-memory buffer of blocks.
 ///
 pub struct BlockBuf {
-    pub blocks: Vec<Bytes>,
+    pub blocks: Vec<IoBuffer>,
 }
 impl BlockWriter for BlockBuf {
-    fn write_blk(&mut self, buf: Bytes) -> Result<u32, std::io::Error> {
+    fn write_blk(&mut self, buf: IoBuffer) -> Result<u32, std::io::Error> {
         assert!(buf.len() == PAGE_SZ);
         let blknum = self.blocks.len();
         self.blocks.push(buf);
diff --git a/pageserver/src/tenant/disk_btree.rs b/pageserver/src/tenant/disk_btree.rs
index 1791e5996c..419befa41b 100644
--- a/pageserver/src/tenant/disk_btree.rs
+++ b/pageserver/src/tenant/disk_btree.rs
@@ -25,7 +25,7 @@ use std::{io, result};
 
 use async_stream::try_stream;
 use byteorder::{BE, ReadBytesExt};
-use bytes::{BufMut, Bytes, BytesMut};
+use bytes::BufMut;
 use either::Either;
 use futures::{Stream, StreamExt};
 use hex;
@@ -34,6 +34,7 @@ use tracing::error;
 
 use crate::context::RequestContext;
 use crate::tenant::block_io::{BlockReader, BlockWriter};
+use crate::virtual_file::{IoBuffer, IoBufferMut, owned_buffers_io::write::Buffer};
 
 // The maximum size of a value stored in the B-tree. 5 bytes is enough currently.
 pub const VALUE_SZ: usize = 5;
@@ -787,12 +788,12 @@ impl<const L: usize> BuildNode<L> {
     ///
     /// Serialize the node to on-disk format.
     ///
-    fn pack(&self) -> Bytes {
+    fn pack(&self) -> IoBuffer {
         assert!(self.keys.len() == self.num_children as usize * self.suffix_len);
         assert!(self.values.len() == self.num_children as usize * VALUE_SZ);
         assert!(self.num_children > 0);
 
-        let mut buf = BytesMut::new();
+        let mut buf = IoBufferMut::with_capacity(PAGE_SZ);
 
         buf.put_u16(self.num_children);
         buf.put_u8(self.level);
@@ -805,7 +806,7 @@ impl<const L: usize> BuildNode<L> {
         assert!(buf.len() == self.size);
 
         assert!(buf.len() <= PAGE_SZ);
-        buf.resize(PAGE_SZ, 0);
+        buf.extend_with(0, PAGE_SZ - buf.len());
         buf.freeze()
     }
 
@@ -839,7 +840,7 @@ pub(crate) mod tests {
 
     #[derive(Clone, Default)]
     pub(crate) struct TestDisk {
-        blocks: Vec<Bytes>,
+        blocks: Vec<IoBuffer>,
     }
     impl TestDisk {
         fn new() -> Self {
@@ -857,7 +858,7 @@ pub(crate) mod tests {
         }
     }
     impl BlockWriter for &mut TestDisk {
-        fn write_blk(&mut self, buf: Bytes) -> io::Result<u32> {
+        fn write_blk(&mut self, buf: IoBuffer) -> io::Result<u32> {
             let blknum = self.blocks.len();
             self.blocks.push(buf);
             Ok(blknum as u32)
diff --git a/pageserver/src/tenant/ephemeral_file.rs b/pageserver/src/tenant/ephemeral_file.rs
index 19215bb918..2edf22e9fd 100644
--- a/pageserver/src/tenant/ephemeral_file.rs
+++ b/pageserver/src/tenant/ephemeral_file.rs
@@ -12,6 +12,7 @@ use tokio_epoll_uring::{BoundedBuf, Slice};
 use tokio_util::sync::CancellationToken;
 use tracing::{error, info_span};
 use utils::id::TimelineId;
+use utils::sync::gate::GateGuard;
 
 use crate::assert_u64_eq_usize::{U64IsUsize, UsizeIsU64};
 use crate::config::PageServerConf;
@@ -21,16 +22,33 @@ use crate::tenant::storage_layer::inmemory_layer::vectored_dio_read::File;
 use crate::virtual_file::owned_buffers_io::io_buf_aligned::IoBufAlignedMut;
 use crate::virtual_file::owned_buffers_io::slice::SliceMutExt;
 use crate::virtual_file::owned_buffers_io::write::{Buffer, FlushTaskError};
-use crate::virtual_file::{self, IoBufferMut, VirtualFile, owned_buffers_io};
+use crate::virtual_file::{self, IoBufferMut, TempVirtualFile, VirtualFile, owned_buffers_io};
+
+use self::owned_buffers_io::write::OwnedAsyncWriter;
 
 pub struct EphemeralFile {
     _tenant_shard_id: TenantShardId,
     _timeline_id: TimelineId,
     page_cache_file_id: page_cache::FileId,
     bytes_written: u64,
-    buffered_writer: owned_buffers_io::write::BufferedWriter<IoBufferMut, VirtualFile>,
-    /// Gate guard is held on as long as we need to do operations in the path (delete on drop)
-    _gate_guard: utils::sync::gate::GateGuard,
+    file: TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter,
+    buffered_writer: BufferedWriter,
+}
+
+type BufferedWriter = owned_buffers_io::write::BufferedWriter<
+    IoBufferMut,
+    TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter,
+>;
+
+/// A TempVirtualFile that is co-owned by the [`EphemeralFile`]` and [`BufferedWriter`].
+///
+/// (Actually [`BufferedWriter`] internally is just a client to a background flush task.
+/// The co-ownership is between [`EphemeralFile`] and that flush task.)
+///
+/// Co-ownership allows us to serve reads for data that has already been flushed by the [`BufferedWriter`].
+#[derive(Debug, Clone)]
+struct TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter {
+    inner: Arc<TempVirtualFile>,
 }
 
 const TAIL_SZ: usize = 64 * 1024;
@@ -44,9 +62,12 @@ impl EphemeralFile {
         cancel: &CancellationToken,
         ctx: &RequestContext,
     ) -> anyhow::Result<EphemeralFile> {
-        static NEXT_FILENAME: AtomicU64 = AtomicU64::new(1);
+        // TempVirtualFile requires us to never reuse a filename while an old
+        // instance of TempVirtualFile created with that filename is not done dropping yet.
+        // So, we use a monotonic counter to disambiguate the filenames.
+        static NEXT_TEMP_DISAMBIGUATOR: AtomicU64 = AtomicU64::new(1);
         let filename_disambiguator =
-            NEXT_FILENAME.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+            NEXT_TEMP_DISAMBIGUATOR.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
 
         let filename = conf
             .timeline_path(&tenant_shard_id, &timeline_id)
@@ -54,16 +75,17 @@ impl EphemeralFile {
                 "ephemeral-{filename_disambiguator}"
             )));
 
-        let file = Arc::new(
+        let file = TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter::new(
             VirtualFile::open_with_options_v2(
                 &filename,
                 virtual_file::OpenOptions::new()
+                    .create_new(true)
                     .read(true)
-                    .write(true)
-                    .create(true),
+                    .write(true),
                 ctx,
             )
             .await?,
+            gate.enter()?,
         );
 
         let page_cache_file_id = page_cache::next_file_id(); // XXX get rid, we're not page-caching anymore
@@ -73,37 +95,60 @@ impl EphemeralFile {
             _timeline_id: timeline_id,
             page_cache_file_id,
             bytes_written: 0,
-            buffered_writer: owned_buffers_io::write::BufferedWriter::new(
+            file: file.clone(),
+            buffered_writer: BufferedWriter::new(
                 file,
+                0,
                 || IoBufferMut::with_capacity(TAIL_SZ),
                 gate.enter()?,
                 cancel.child_token(),
                 ctx,
                 info_span!(parent: None, "ephemeral_file_buffered_writer", tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(), timeline_id=%timeline_id, path = %filename),
             ),
-            _gate_guard: gate.enter()?,
         })
     }
 }
 
-impl Drop for EphemeralFile {
-    fn drop(&mut self) {
-        // unlink the file
-        // we are clear to do this, because we have entered a gate
-        let path = self.buffered_writer.as_inner().path();
-        let res = std::fs::remove_file(path);
-        if let Err(e) = res {
-            if e.kind() != std::io::ErrorKind::NotFound {
-                // just never log the not found errors, we cannot do anything for them; on detach
-                // the tenant directory is already gone.
-                //
-                // not found files might also be related to https://github.com/neondatabase/neon/issues/2442
-                error!("could not remove ephemeral file '{path}': {e}");
-            }
+impl TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter {
+    fn new(file: VirtualFile, gate_guard: GateGuard) -> Self {
+        Self {
+            inner: Arc::new(TempVirtualFile::new(file, gate_guard)),
         }
     }
 }
 
+impl OwnedAsyncWriter for TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter {
+    fn write_all_at<Buf: owned_buffers_io::io_buf_aligned::IoBufAligned + Send>(
+        &self,
+        buf: owned_buffers_io::io_buf_ext::FullSlice<Buf>,
+        offset: u64,
+        ctx: &RequestContext,
+    ) -> impl std::future::Future<
+        Output = (
+            owned_buffers_io::io_buf_ext::FullSlice<Buf>,
+            std::io::Result<()>,
+        ),
+    > + Send {
+        self.inner.write_all_at(buf, offset, ctx)
+    }
+
+    fn set_len(
+        &self,
+        len: u64,
+        ctx: &RequestContext,
+    ) -> impl Future<Output = std::io::Result<()>> + Send {
+        self.inner.set_len(len, ctx)
+    }
+}
+
+impl std::ops::Deref for TempVirtualFileCoOwnedByEphemeralFileAndBufferedWriter {
+    type Target = VirtualFile;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
 #[derive(Debug, thiserror::Error)]
 pub(crate) enum EphemeralFileWriteError {
     #[error("{0}")]
@@ -262,9 +307,9 @@ impl super::storage_layer::inmemory_layer::vectored_dio_read::File for Ephemeral
         let mutable_range = Range(std::cmp::max(start, submitted_offset), end);
 
         let dst = if written_range.len() > 0 {
-            let file: &VirtualFile = self.buffered_writer.as_inner();
             let bounds = dst.bounds();
-            let slice = file
+            let slice = self
+                .file
                 .read_exact_at(dst.slice(0..written_range.len().into_usize()), start, ctx)
                 .await?;
             Slice::from_buf_bounds(Slice::into_inner(slice), bounds)
@@ -456,7 +501,7 @@ mod tests {
             assert_eq!(&buf, &content[range]);
         }
 
-        let file_contents = std::fs::read(file.buffered_writer.as_inner().path()).unwrap();
+        let file_contents = std::fs::read(file.file.path()).unwrap();
         assert!(file_contents == content[0..cap * 2]);
 
         let maybe_flushed_buffer_contents = file.buffered_writer.inspect_maybe_flushed().unwrap();
@@ -489,7 +534,7 @@ mod tests {
         // assert the state is as this test expects it to be
         let load_io_buf_res = file.load_to_io_buf(&ctx).await.unwrap();
         assert_eq!(&load_io_buf_res[..], &content[0..cap * 2 + cap / 2]);
-        let md = file.buffered_writer.as_inner().path().metadata().unwrap();
+        let md = file.file.path().metadata().unwrap();
         assert_eq!(
             md.len(),
             2 * cap.into_u64(),
diff --git a/pageserver/src/tenant/remote_timeline_client/download.rs b/pageserver/src/tenant/remote_timeline_client/download.rs
index 70f77ef9e8..84989e0fb8 100644
--- a/pageserver/src/tenant/remote_timeline_client/download.rs
+++ b/pageserver/src/tenant/remote_timeline_client/download.rs
@@ -6,6 +6,7 @@
 use std::collections::HashSet;
 use std::future::Future;
 use std::str::FromStr;
+use std::sync::atomic::AtomicU64;
 use std::time::SystemTime;
 
 use anyhow::{Context, anyhow};
@@ -15,7 +16,7 @@ use remote_storage::{
     DownloadError, DownloadKind, DownloadOpts, GenericRemoteStorage, ListingMode, RemotePath,
 };
 use tokio::fs::{self, File, OpenOptions};
-use tokio::io::{AsyncSeekExt, AsyncWriteExt};
+use tokio::io::AsyncSeekExt;
 use tokio_util::io::StreamReader;
 use tokio_util::sync::CancellationToken;
 use tracing::warn;
@@ -40,7 +41,10 @@ use crate::span::{
 use crate::tenant::Generation;
 use crate::tenant::remote_timeline_client::{remote_layer_path, remote_timelines_path};
 use crate::tenant::storage_layer::LayerName;
-use crate::virtual_file::{MaybeFatalIo, VirtualFile, on_fatal_io_error};
+use crate::virtual_file;
+use crate::virtual_file::owned_buffers_io::write::FlushTaskError;
+use crate::virtual_file::{IoBufferMut, MaybeFatalIo, VirtualFile};
+use crate::virtual_file::{TempVirtualFile, owned_buffers_io};
 
 ///
 /// If 'metadata' is given, we will validate that the downloaded file's size matches that
@@ -72,21 +76,34 @@ pub async fn download_layer_file<'a>(
         layer_metadata.generation,
     );
 
-    // Perform a rename inspired by durable_rename from file_utils.c.
-    // The sequence:
-    //     write(tmp)
-    //     fsync(tmp)
-    //     rename(tmp, new)
-    //     fsync(new)
-    //     fsync(parent)
-    // For more context about durable_rename check this email from postgres mailing list:
-    // https://www.postgresql.org/message-id/56583BDD.9060302@2ndquadrant.com
-    // If pageserver crashes the temp file will be deleted on startup and re-downloaded.
-    let temp_file_path = path_with_suffix_extension(local_path, TEMP_DOWNLOAD_EXTENSION);
-
-    let bytes_amount = download_retry(
+    let (bytes_amount, temp_file) = download_retry(
         || async {
-            download_object(storage, &remote_path, &temp_file_path, gate, cancel, ctx).await
+            // TempVirtualFile requires us to never reuse a filename while an old
+            // instance of TempVirtualFile created with that filename is not done dropping yet.
+            // So, we use a monotonic counter to disambiguate the filenames.
+            static NEXT_TEMP_DISAMBIGUATOR: AtomicU64 = AtomicU64::new(1);
+            let filename_disambiguator =
+                NEXT_TEMP_DISAMBIGUATOR.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
+            let temp_file_path = path_with_suffix_extension(
+                local_path,
+                &format!("{filename_disambiguator:x}.{TEMP_DOWNLOAD_EXTENSION}"),
+            );
+
+            let temp_file = TempVirtualFile::new(
+                VirtualFile::open_with_options_v2(
+                    &temp_file_path,
+                    virtual_file::OpenOptions::new()
+                        .create_new(true)
+                        .write(true),
+                    ctx,
+                )
+                .await
+                .with_context(|| format!("create a temp file for layer download: {temp_file_path}"))
+                .map_err(DownloadError::Other)?,
+                gate.enter().map_err(|_| DownloadError::Cancelled)?,
+            );
+            download_object(storage, &remote_path, temp_file, gate, cancel, ctx).await
         },
         &format!("download {remote_path:?}"),
         cancel,
@@ -96,7 +113,8 @@ pub async fn download_layer_file<'a>(
     let expected = layer_metadata.file_size;
     if expected != bytes_amount {
         return Err(DownloadError::Other(anyhow!(
-            "According to layer file metadata should have downloaded {expected} bytes but downloaded {bytes_amount} bytes into file {temp_file_path:?}",
+            "According to layer file metadata should have downloaded {expected} bytes but downloaded {bytes_amount} bytes into file {:?}",
+            temp_file.path()
         )));
     }
 
@@ -106,11 +124,28 @@ pub async fn download_layer_file<'a>(
         )))
     });
 
-    fs::rename(&temp_file_path, &local_path)
+    // Try rename before disarming the temp file.
+    // That way, if rename fails for whatever reason, we clean up the temp file on the return path.
+
+    fs::rename(temp_file.path(), &local_path)
         .await
         .with_context(|| format!("rename download layer file to {local_path}"))
         .map_err(DownloadError::Other)?;
 
+    // The temp file's VirtualFile points to the temp_file_path which we moved above.
+    // Drop it immediately, it's invalid.
+    // This will get better in https://github.com/neondatabase/neon/issues/11692
+    let _: VirtualFile = temp_file.disarm_into_inner();
+    // NB: The gate guard that was stored in `temp_file` is dropped but we continue
+    // to operate on it and on the parent timeline directory.
+    // Those operations are safe to do because higher-level code is holding another gate guard:
+    // - attached mode: the download task spawned by struct Layer is holding the gate guard
+    // - secondary mode: The TenantDownloader::download holds the gate open
+
+    // The rename above is not durable yet.
+    // It doesn't matter for crash consistency because pageserver startup deletes temp
+    // files and we'll re-download on demand if necessary.
+
     // We use fatal_err() below because the after the rename above,
     // the in-memory state of the filesystem already has the layer file in its final place,
     // and subsequent pageserver code could think it's durable while it really isn't.
@@ -146,147 +181,64 @@ pub async fn download_layer_file<'a>(
 async fn download_object(
     storage: &GenericRemoteStorage,
     src_path: &RemotePath,
-    dst_path: &Utf8PathBuf,
-    #[cfg_attr(target_os = "macos", allow(unused_variables))] gate: &utils::sync::gate::Gate,
+    destination_file: TempVirtualFile,
+    gate: &utils::sync::gate::Gate,
     cancel: &CancellationToken,
-    #[cfg_attr(target_os = "macos", allow(unused_variables))] ctx: &RequestContext,
-) -> Result<u64, DownloadError> {
-    let res = match crate::virtual_file::io_engine::get() {
-        crate::virtual_file::io_engine::IoEngine::NotSet => panic!("unset"),
-        crate::virtual_file::io_engine::IoEngine::StdFs => {
-            async {
-                let destination_file = tokio::fs::File::create(dst_path)
-                    .await
-                    .with_context(|| format!("create a destination file for layer '{dst_path}'"))
-                    .map_err(DownloadError::Other)?;
+    ctx: &RequestContext,
+) -> Result<(u64, TempVirtualFile), DownloadError> {
+    let mut download = storage
+        .download(src_path, &DownloadOpts::default(), cancel)
+        .await?;
 
-                let download = storage
-                    .download(src_path, &DownloadOpts::default(), cancel)
-                    .await?;
+    pausable_failpoint!("before-downloading-layer-stream-pausable");
 
-                pausable_failpoint!("before-downloading-layer-stream-pausable");
+    let dst_path = destination_file.path().to_owned();
+    let mut buffered = owned_buffers_io::write::BufferedWriter::<IoBufferMut, _>::new(
+        destination_file,
+        0,
+        || IoBufferMut::with_capacity(super::BUFFER_SIZE),
+        gate.enter().map_err(|_| DownloadError::Cancelled)?,
+        cancel.child_token(),
+        ctx,
+        tracing::info_span!(parent: None, "download_object_buffered_writer", %dst_path),
+    );
 
-                let mut buf_writer =
-                    tokio::io::BufWriter::with_capacity(super::BUFFER_SIZE, destination_file);
-
-                let mut reader = tokio_util::io::StreamReader::new(download.download_stream);
-
-                let bytes_amount = tokio::io::copy_buf(&mut reader, &mut buf_writer).await?;
-                buf_writer.flush().await?;
-
-                let mut destination_file = buf_writer.into_inner();
-
-                // Tokio doc here: https://docs.rs/tokio/1.17.0/tokio/fs/struct.File.html states that:
-                // A file will not be closed immediately when it goes out of scope if there are any IO operations
-                // that have not yet completed. To ensure that a file is closed immediately when it is dropped,
-                // you should call flush before dropping it.
-                //
-                // From the tokio code I see that it waits for pending operations to complete. There shouldt be any because
-                // we assume that `destination_file` file is fully written. I e there is no pending .write(...).await operations.
-                // But for additional safety lets check/wait for any pending operations.
-                destination_file
-                    .flush()
-                    .await
-                    .maybe_fatal_err("download_object sync_all")
-                    .with_context(|| format!("flush source file at {dst_path}"))
-                    .map_err(DownloadError::Other)?;
-
-                // not using sync_data because it can lose file size update
-                destination_file
-                    .sync_all()
-                    .await
-                    .maybe_fatal_err("download_object sync_all")
-                    .with_context(|| format!("failed to fsync source file at {dst_path}"))
-                    .map_err(DownloadError::Other)?;
-
-                Ok(bytes_amount)
-            }
+    // TODO: use vectored write (writev) once supported by tokio-epoll-uring.
+    // There's chunks_vectored() on the stream.
+    let (bytes_amount, destination_file) = async {
+        while let Some(res) = futures::StreamExt::next(&mut download.download_stream).await {
+            let chunk = match res {
+                Ok(chunk) => chunk,
+                Err(e) => return Err(DownloadError::from(e)),
+            };
+            buffered
+                .write_buffered_borrowed(&chunk, ctx)
+                .await
+                .map_err(|e| match e {
+                    FlushTaskError::Cancelled => DownloadError::Cancelled,
+                })?;
+        }
+        buffered
+            .shutdown(
+                owned_buffers_io::write::BufferedWriterShutdownMode::PadThenTruncate,
+                ctx,
+            )
             .await
-        }
-        #[cfg(target_os = "linux")]
-        crate::virtual_file::io_engine::IoEngine::TokioEpollUring => {
-            use crate::virtual_file::owned_buffers_io::write::FlushTaskError;
-            use std::sync::Arc;
-
-            use crate::virtual_file::{IoBufferMut, owned_buffers_io};
-            async {
-                let destination_file = Arc::new(
-                    VirtualFile::create(dst_path, ctx)
-                        .await
-                        .with_context(|| {
-                            format!("create a destination file for layer '{dst_path}'")
-                        })
-                        .map_err(DownloadError::Other)?,
-                );
-
-                let mut download = storage
-                    .download(src_path, &DownloadOpts::default(), cancel)
-                    .await?;
-
-                pausable_failpoint!("before-downloading-layer-stream-pausable");
-
-                let mut buffered = owned_buffers_io::write::BufferedWriter::<IoBufferMut, _>::new(
-                    destination_file,
-                    || IoBufferMut::with_capacity(super::BUFFER_SIZE),
-                    gate.enter().map_err(|_| DownloadError::Cancelled)?,
-                    cancel.child_token(),
-                    ctx,
-                    tracing::info_span!(parent: None, "download_object_buffered_writer", %dst_path),
-                );
-
-                // TODO: use vectored write (writev) once supported by tokio-epoll-uring.
-                // There's chunks_vectored() on the stream.
-                let (bytes_amount, destination_file) = async {
-                    while let Some(res) =
-                        futures::StreamExt::next(&mut download.download_stream).await
-                    {
-                        let chunk = match res {
-                            Ok(chunk) => chunk,
-                            Err(e) => return Err(DownloadError::from(e)),
-                        };
-                        buffered
-                            .write_buffered_borrowed(&chunk, ctx)
-                            .await
-                            .map_err(|e| match e {
-                                FlushTaskError::Cancelled => DownloadError::Cancelled,
-                            })?;
-                    }
-                    let inner = buffered
-                        .flush_and_into_inner(ctx)
-                        .await
-                        .map_err(|e| match e {
-                            FlushTaskError::Cancelled => DownloadError::Cancelled,
-                        })?;
-                    Ok(inner)
-                }
-                .await?;
-
-                // not using sync_data because it can lose file size update
-                destination_file
-                    .sync_all()
-                    .await
-                    .maybe_fatal_err("download_object sync_all")
-                    .with_context(|| format!("failed to fsync source file at {dst_path}"))
-                    .map_err(DownloadError::Other)?;
-
-                Ok(bytes_amount)
-            }
-            .await
-        }
-    };
-
-    // in case the download failed, clean up
-    match res {
-        Ok(bytes_amount) => Ok(bytes_amount),
-        Err(e) => {
-            if let Err(e) = tokio::fs::remove_file(dst_path).await {
-                if e.kind() != std::io::ErrorKind::NotFound {
-                    on_fatal_io_error(&e, &format!("Removing temporary file {dst_path}"));
-                }
-            }
-            Err(e)
-        }
+            .map_err(|e| match e {
+                FlushTaskError::Cancelled => DownloadError::Cancelled,
+            })
     }
+    .await?;
+
+    // not using sync_data because it can lose file size update
+    destination_file
+        .sync_all()
+        .await
+        .maybe_fatal_err("download_object sync_all")
+        .with_context(|| format!("failed to fsync source file at {dst_path}"))
+        .map_err(DownloadError::Other)?;
+
+    Ok((bytes_amount, destination_file))
 }
 
 const TEMP_DOWNLOAD_EXTENSION: &str = "temp_download";
diff --git a/pageserver/src/tenant/secondary/downloader.rs b/pageserver/src/tenant/secondary/downloader.rs
index 60cf7ac79e..c26b7626ef 100644
--- a/pageserver/src/tenant/secondary/downloader.rs
+++ b/pageserver/src/tenant/secondary/downloader.rs
@@ -646,7 +646,7 @@ enum UpdateError {
     NoData,
     #[error("Insufficient local storage space")]
     NoSpace,
-    #[error("Failed to download")]
+    #[error("Failed to download: {0}")]
     DownloadError(DownloadError),
     #[error(transparent)]
     Deserialize(#[from] serde_json::Error),
@@ -1521,12 +1521,11 @@ async fn load_heatmap(
     path: &Utf8PathBuf,
     ctx: &RequestContext,
 ) -> Result<Option<HeatMapTenant>, anyhow::Error> {
-    let mut file = match VirtualFile::open(path, ctx).await {
-        Ok(file) => file,
+    let st = match VirtualFile::read_to_string(path, ctx).await {
+        Ok(st) => st,
         Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(None),
         Err(e) => Err(e)?,
     };
-    let st = file.read_to_string(ctx).await?;
     let htm = serde_json::from_str(&st)?;
     Ok(Some(htm))
 }
diff --git a/pageserver/src/tenant/storage_layer/delta_layer.rs b/pageserver/src/tenant/storage_layer/delta_layer.rs
index 0654342a25..607b0d513c 100644
--- a/pageserver/src/tenant/storage_layer/delta_layer.rs
+++ b/pageserver/src/tenant/storage_layer/delta_layer.rs
@@ -29,11 +29,11 @@
 //!
 use std::collections::{HashMap, VecDeque};
 use std::fs::File;
-use std::io::SeekFrom;
 use std::ops::Range;
 use std::os::unix::fs::FileExt;
 use std::str::FromStr;
 use std::sync::Arc;
+use std::sync::atomic::AtomicU64;
 
 use anyhow::{Context, Result, bail, ensure};
 use camino::{Utf8Path, Utf8PathBuf};
@@ -45,14 +45,13 @@ use pageserver_api::keyspace::KeySpace;
 use pageserver_api::models::ImageCompressionAlgorithm;
 use pageserver_api::shard::TenantShardId;
 use pageserver_api::value::Value;
-use rand::Rng;
-use rand::distributions::Alphanumeric;
 use serde::{Deserialize, Serialize};
 use tokio::sync::OnceCell;
 use tokio_epoll_uring::IoBuf;
 use tokio_util::sync::CancellationToken;
 use tracing::*;
 use utils::bin_ser::BeSer;
+use utils::bin_ser::SerializeError;
 use utils::id::{TenantId, TimelineId};
 use utils::lsn::Lsn;
 
@@ -74,8 +73,10 @@ use crate::tenant::vectored_blob_io::{
     BlobFlag, BufView, StreamingVectoredReadPlanner, VectoredBlobReader, VectoredRead,
     VectoredReadPlanner,
 };
+use crate::virtual_file::TempVirtualFile;
 use crate::virtual_file::owned_buffers_io::io_buf_ext::{FullSlice, IoBufExt};
-use crate::virtual_file::{self, IoBufferMut, MaybeFatalIo, VirtualFile};
+use crate::virtual_file::owned_buffers_io::write::{Buffer, BufferedWriterShutdownMode};
+use crate::virtual_file::{self, IoBuffer, IoBufferMut, MaybeFatalIo, VirtualFile};
 use crate::{DELTA_FILE_MAGIC, STORAGE_FORMAT_VERSION, TEMP_FILE_SUFFIX};
 
 ///
@@ -113,6 +114,15 @@ impl From<&DeltaLayer> for Summary {
 }
 
 impl Summary {
+    /// Serializes the summary header into an aligned buffer of lenth `PAGE_SZ`.
+    pub fn ser_into_page(&self) -> Result<IoBuffer, SerializeError> {
+        let mut buf = IoBufferMut::with_capacity(PAGE_SZ);
+        Self::ser_into(self, &mut buf)?;
+        // Pad zeroes to the buffer so the length is a multiple of the alignment.
+        buf.extend_with(0, buf.capacity() - buf.len());
+        Ok(buf.freeze())
+    }
+
     pub(super) fn expected(
         tenant_id: TenantId,
         timeline_id: TimelineId,
@@ -288,19 +298,20 @@ impl DeltaLayer {
         key_start: Key,
         lsn_range: &Range<Lsn>,
     ) -> Utf8PathBuf {
-        let rand_string: String = rand::thread_rng()
-            .sample_iter(&Alphanumeric)
-            .take(8)
-            .map(char::from)
-            .collect();
+        // TempVirtualFile requires us to never reuse a filename while an old
+        // instance of TempVirtualFile created with that filename is not done dropping yet.
+        // So, we use a monotonic counter to disambiguate the filenames.
+        static NEXT_TEMP_DISAMBIGUATOR: AtomicU64 = AtomicU64::new(1);
+        let filename_disambiguator =
+            NEXT_TEMP_DISAMBIGUATOR.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
 
         conf.timeline_path(tenant_shard_id, timeline_id)
             .join(format!(
-                "{}-XXX__{:016X}-{:016X}.{}.{}",
+                "{}-XXX__{:016X}-{:016X}.{:x}.{}",
                 key_start,
                 u64::from(lsn_range.start),
                 u64::from(lsn_range.end),
-                rand_string,
+                filename_disambiguator,
                 TEMP_FILE_SUFFIX,
             ))
     }
@@ -391,7 +402,7 @@ struct DeltaLayerWriterInner {
 
     tree: DiskBtreeBuilder<BlockBuf, DELTA_KEY_SIZE>,
 
-    blob_writer: BlobWriter<true>,
+    blob_writer: BlobWriter<TempVirtualFile>,
 
     // Number of key-lsns in the layer.
     num_keys: usize,
@@ -415,16 +426,29 @@ impl DeltaLayerWriterInner {
         // Create the file initially with a temporary filename. We don't know
         // the end key yet, so we cannot form the final filename yet. We will
         // rename it when we're done.
-        //
-        // Note: This overwrites any existing file. There shouldn't be any.
-        // FIXME: throw an error instead?
         let path =
             DeltaLayer::temp_path_for(conf, &tenant_shard_id, &timeline_id, key_start, &lsn_range);
+        let file = TempVirtualFile::new(
+            VirtualFile::open_with_options_v2(
+                &path,
+                virtual_file::OpenOptions::new()
+                    .create_new(true)
+                    .write(true),
+                ctx,
+            )
+            .await?,
+            gate.enter()?,
+        );
 
-        let mut file = VirtualFile::create(&path, ctx).await?;
-        // make room for the header block
-        file.seek(SeekFrom::Start(PAGE_SZ as u64)).await?;
-        let blob_writer = BlobWriter::new(file, PAGE_SZ as u64, gate, cancel, ctx);
+        // Start at PAGE_SZ, make room for the header block
+        let blob_writer = BlobWriter::new(
+            file,
+            PAGE_SZ as u64,
+            gate,
+            cancel,
+            ctx,
+            info_span!(parent: None, "delta_layer_writer_flush_task", tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(), timeline_id=%timeline_id, path = %path),
+        )?;
 
         // Initialize the b-tree index builder
         let block_buf = BlockBuf::new();
@@ -515,34 +539,27 @@ impl DeltaLayerWriterInner {
         self,
         key_end: Key,
         ctx: &RequestContext,
-    ) -> anyhow::Result<(PersistentLayerDesc, Utf8PathBuf)> {
-        let temp_path = self.path.clone();
-        let result = self.finish0(key_end, ctx).await;
-        if let Err(ref e) = result {
-            tracing::info!(%temp_path, "cleaning up temporary file after error during writing: {e}");
-            if let Err(e) = std::fs::remove_file(&temp_path) {
-                tracing::warn!(error=%e, %temp_path, "error cleaning up temporary layer file after error during writing");
-            }
-        }
-        result
-    }
-
-    async fn finish0(
-        self,
-        key_end: Key,
-        ctx: &RequestContext,
     ) -> anyhow::Result<(PersistentLayerDesc, Utf8PathBuf)> {
         let index_start_blk = self.blob_writer.size().div_ceil(PAGE_SZ as u64) as u32;
 
-        let mut file = self.blob_writer.into_inner(ctx).await?;
+        let file = self
+            .blob_writer
+            .shutdown(
+                BufferedWriterShutdownMode::ZeroPadToNextMultiple(PAGE_SZ),
+                ctx,
+            )
+            .await?;
 
         // Write out the index
         let (index_root_blk, block_buf) = self.tree.finish()?;
-        file.seek(SeekFrom::Start(index_start_blk as u64 * PAGE_SZ as u64))
-            .await?;
+        let mut offset = index_start_blk as u64 * PAGE_SZ as u64;
+
+        // TODO(yuchen): https://github.com/neondatabase/neon/issues/10092
+        // Should we just replace BlockBuf::blocks with one big buffer
         for buf in block_buf.blocks {
-            let (_buf, res) = file.write_all(buf.slice_len(), ctx).await;
+            let (_buf, res) = file.write_all_at(buf.slice_len(), offset, ctx).await;
             res?;
+            offset += PAGE_SZ as u64;
         }
         assert!(self.lsn_range.start < self.lsn_range.end);
         // Fill in the summary on blk 0
@@ -557,11 +574,9 @@ impl DeltaLayerWriterInner {
             index_root_blk,
         };
 
-        let mut buf = Vec::with_capacity(PAGE_SZ);
-        // TODO: could use smallvec here but it's a pain with Slice<T>
-        Summary::ser_into(&summary, &mut buf)?;
-        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf.slice_len(), ctx).await;
+        // Writes summary at the first block (offset 0).
+        let buf = summary.ser_into_page()?;
+        let (_buf, res) = file.write_all_at(buf.slice_len(), 0, ctx).await;
         res?;
 
         let metadata = file
@@ -598,6 +613,10 @@ impl DeltaLayerWriterInner {
 
         trace!("created delta layer {}", self.path);
 
+        // The gate guard stored in `destination_file` is dropped. Callers (e.g.. flush loop or compaction)
+        // keep the gate open also, so that it's safe for them to rename the file to its final destination.
+        file.disarm_into_inner();
+
         Ok((desc, self.path))
     }
 }
@@ -726,17 +745,6 @@ impl DeltaLayerWriter {
     }
 }
 
-impl Drop for DeltaLayerWriter {
-    fn drop(&mut self) {
-        if let Some(inner) = self.inner.take() {
-            // We want to remove the virtual file here, so it's fine to not
-            // having completely flushed unwritten data.
-            let vfile = inner.blob_writer.into_inner_no_flush();
-            vfile.remove();
-        }
-    }
-}
-
 #[derive(thiserror::Error, Debug)]
 pub enum RewriteSummaryError {
     #[error("magic mismatch")]
@@ -760,7 +768,7 @@ impl DeltaLayer {
     where
         F: Fn(Summary) -> Summary,
     {
-        let mut file = VirtualFile::open_with_options(
+        let file = VirtualFile::open_with_options_v2(
             path,
             virtual_file::OpenOptions::new().read(true).write(true),
             ctx,
@@ -777,11 +785,8 @@ impl DeltaLayer {
 
         let new_summary = rewrite(actual_summary);
 
-        let mut buf = Vec::with_capacity(PAGE_SZ);
-        // TODO: could use smallvec here, but it's a pain with Slice<T>
-        Summary::ser_into(&new_summary, &mut buf).context("serialize")?;
-        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf.slice_len(), ctx).await;
+        let buf = new_summary.ser_into_page().context("serialize")?;
+        let (_buf, res) = file.write_all_at(buf.slice_len(), 0, ctx).await;
         res?;
         Ok(())
     }
@@ -1437,6 +1442,19 @@ impl DeltaLayerInner {
     }
 
     pub fn iter<'a>(&'a self, ctx: &'a RequestContext) -> DeltaLayerIterator<'a> {
+        self.iter_with_options(
+            ctx,
+            1024 * 8192, // The default value. Unit tests might use a different value. 1024 * 8K = 8MB buffer.
+            1024,        // The default value. Unit tests might use a different value
+        )
+    }
+
+    pub fn iter_with_options<'a>(
+        &'a self,
+        ctx: &'a RequestContext,
+        max_read_size: u64,
+        max_batch_size: usize,
+    ) -> DeltaLayerIterator<'a> {
         let block_reader = FileBlockReader::new(&self.file, self.file_id);
         let tree_reader =
             DiskBtreeReader::new(self.index_start_blk, self.index_root_blk, block_reader);
@@ -1446,10 +1464,7 @@ impl DeltaLayerInner {
             index_iter: tree_reader.iter(&[0; DELTA_KEY_SIZE], ctx),
             key_values_batch: std::collections::VecDeque::new(),
             is_end: false,
-            planner: StreamingVectoredReadPlanner::new(
-                1024 * 8192, // The default value. Unit tests might use a different value. 1024 * 8K = 8MB buffer.
-                1024,        // The default value. Unit tests might use a different value
-            ),
+            planner: StreamingVectoredReadPlanner::new(max_read_size, max_batch_size),
         }
     }
 
@@ -1609,8 +1624,8 @@ pub(crate) mod test {
     use bytes::Bytes;
     use itertools::MinMaxResult;
     use pageserver_api::value::Value;
-    use rand::RngCore;
     use rand::prelude::{SeedableRng, SliceRandom, StdRng};
+    use rand::{Rng, RngCore};
 
     use super::*;
     use crate::DEFAULT_PG_VERSION;
diff --git a/pageserver/src/tenant/storage_layer/image_layer.rs b/pageserver/src/tenant/storage_layer/image_layer.rs
index 8ee4cdee66..2f7c5715bb 100644
--- a/pageserver/src/tenant/storage_layer/image_layer.rs
+++ b/pageserver/src/tenant/storage_layer/image_layer.rs
@@ -27,11 +27,11 @@
 //! actual page images are stored in the "values" part.
 use std::collections::{HashMap, VecDeque};
 use std::fs::File;
-use std::io::SeekFrom;
 use std::ops::Range;
 use std::os::unix::prelude::FileExt;
 use std::str::FromStr;
 use std::sync::Arc;
+use std::sync::atomic::AtomicU64;
 
 use anyhow::{Context, Result, bail, ensure};
 use bytes::Bytes;
@@ -43,14 +43,13 @@ use pageserver_api::key::{DBDIR_KEY, KEY_SIZE, Key};
 use pageserver_api::keyspace::KeySpace;
 use pageserver_api::shard::{ShardIdentity, TenantShardId};
 use pageserver_api::value::Value;
-use rand::Rng;
-use rand::distributions::Alphanumeric;
 use serde::{Deserialize, Serialize};
 use tokio::sync::OnceCell;
 use tokio_stream::StreamExt;
 use tokio_util::sync::CancellationToken;
 use tracing::*;
 use utils::bin_ser::BeSer;
+use utils::bin_ser::SerializeError;
 use utils::id::{TenantId, TimelineId};
 use utils::lsn::Lsn;
 
@@ -72,8 +71,10 @@ use crate::tenant::vectored_blob_io::{
     BlobFlag, BufView, StreamingVectoredReadPlanner, VectoredBlobReader, VectoredRead,
     VectoredReadPlanner,
 };
+use crate::virtual_file::TempVirtualFile;
 use crate::virtual_file::owned_buffers_io::io_buf_ext::IoBufExt;
-use crate::virtual_file::{self, IoBufferMut, MaybeFatalIo, VirtualFile};
+use crate::virtual_file::owned_buffers_io::write::{Buffer, BufferedWriterShutdownMode};
+use crate::virtual_file::{self, IoBuffer, IoBufferMut, MaybeFatalIo, VirtualFile};
 use crate::{IMAGE_FILE_MAGIC, STORAGE_FORMAT_VERSION, TEMP_FILE_SUFFIX};
 
 ///
@@ -112,6 +113,15 @@ impl From<&ImageLayer> for Summary {
 }
 
 impl Summary {
+    /// Serializes the summary header into an aligned buffer of lenth `PAGE_SZ`.
+    pub fn ser_into_page(&self) -> Result<IoBuffer, SerializeError> {
+        let mut buf = IoBufferMut::with_capacity(PAGE_SZ);
+        Self::ser_into(self, &mut buf)?;
+        // Pad zeroes to the buffer so the length is a multiple of the alignment.
+        buf.extend_with(0, buf.capacity() - buf.len());
+        Ok(buf.freeze())
+    }
+
     pub(super) fn expected(
         tenant_id: TenantId,
         timeline_id: TimelineId,
@@ -252,14 +262,18 @@ impl ImageLayer {
         tenant_shard_id: TenantShardId,
         fname: &ImageLayerName,
     ) -> Utf8PathBuf {
-        let rand_string: String = rand::thread_rng()
-            .sample_iter(&Alphanumeric)
-            .take(8)
-            .map(char::from)
-            .collect();
+        // TempVirtualFile requires us to never reuse a filename while an old
+        // instance of TempVirtualFile created with that filename is not done dropping yet.
+        // So, we use a monotonic counter to disambiguate the filenames.
+        static NEXT_TEMP_DISAMBIGUATOR: AtomicU64 = AtomicU64::new(1);
+        let filename_disambiguator =
+            NEXT_TEMP_DISAMBIGUATOR.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
 
         conf.timeline_path(&tenant_shard_id, &timeline_id)
-            .join(format!("{fname}.{rand_string}.{TEMP_FILE_SUFFIX}"))
+            .join(format!(
+                "{fname}.{:x}.{TEMP_FILE_SUFFIX}",
+                filename_disambiguator
+            ))
     }
 
     ///
@@ -349,7 +363,7 @@ impl ImageLayer {
     where
         F: Fn(Summary) -> Summary,
     {
-        let mut file = VirtualFile::open_with_options(
+        let file = VirtualFile::open_with_options_v2(
             path,
             virtual_file::OpenOptions::new().read(true).write(true),
             ctx,
@@ -366,11 +380,8 @@ impl ImageLayer {
 
         let new_summary = rewrite(actual_summary);
 
-        let mut buf = Vec::with_capacity(PAGE_SZ);
-        // TODO: could use smallvec here but it's a pain with Slice<T>
-        Summary::ser_into(&new_summary, &mut buf).context("serialize")?;
-        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf.slice_len(), ctx).await;
+        let buf = new_summary.ser_into_page().context("serialize")?;
+        let (_buf, res) = file.write_all_at(buf.slice_len(), 0, ctx).await;
         res?;
         Ok(())
     }
@@ -674,6 +685,19 @@ impl ImageLayerInner {
     }
 
     pub(crate) fn iter<'a>(&'a self, ctx: &'a RequestContext) -> ImageLayerIterator<'a> {
+        self.iter_with_options(
+            ctx,
+            1024 * 8192, // The default value. Unit tests might use a different value. 1024 * 8K = 8MB buffer.
+            1024,        // The default value. Unit tests might use a different value
+        )
+    }
+
+    pub(crate) fn iter_with_options<'a>(
+        &'a self,
+        ctx: &'a RequestContext,
+        max_read_size: u64,
+        max_batch_size: usize,
+    ) -> ImageLayerIterator<'a> {
         let block_reader = FileBlockReader::new(&self.file, self.file_id);
         let tree_reader =
             DiskBtreeReader::new(self.index_start_blk, self.index_root_blk, block_reader);
@@ -683,10 +707,7 @@ impl ImageLayerInner {
             index_iter: tree_reader.iter(&[0; KEY_SIZE], ctx),
             key_values_batch: VecDeque::new(),
             is_end: false,
-            planner: StreamingVectoredReadPlanner::new(
-                1024 * 8192, // The default value. Unit tests might use a different value. 1024 * 8K = 8MB buffer.
-                1024,        // The default value. Unit tests might use a different value
-            ),
+            planner: StreamingVectoredReadPlanner::new(max_read_size, max_batch_size),
         }
     }
 
@@ -739,7 +760,7 @@ struct ImageLayerWriterInner {
     // Number of keys in the layer.
     num_keys: usize,
 
-    blob_writer: BlobWriter<false>,
+    blob_writer: BlobWriter<TempVirtualFile>,
     tree: DiskBtreeBuilder<BlockBuf, KEY_SIZE>,
 
     #[cfg(feature = "testing")]
@@ -773,19 +794,27 @@ impl ImageLayerWriterInner {
             },
         );
         trace!("creating image layer {}", path);
-        let mut file = {
-            VirtualFile::open_with_options(
+        let file = TempVirtualFile::new(
+            VirtualFile::open_with_options_v2(
                 &path,
                 virtual_file::OpenOptions::new()
-                    .write(true)
-                    .create_new(true),
+                    .create_new(true)
+                    .write(true),
                 ctx,
             )
-            .await?
-        };
-        // make room for the header block
-        file.seek(SeekFrom::Start(PAGE_SZ as u64)).await?;
-        let blob_writer = BlobWriter::new(file, PAGE_SZ as u64, gate, cancel, ctx);
+            .await?,
+            gate.enter()?,
+        );
+
+        // Start at `PAGE_SZ` to make room for the header block.
+        let blob_writer = BlobWriter::new(
+            file,
+            PAGE_SZ as u64,
+            gate,
+            cancel,
+            ctx,
+            info_span!(parent: None, "image_layer_writer_flush_task", tenant_id=%tenant_shard_id.tenant_id, shard_id=%tenant_shard_id.shard_slug(), timeline_id=%timeline_id, path = %path),
+        )?;
 
         // Initialize the b-tree index builder
         let block_buf = BlockBuf::new();
@@ -896,25 +925,6 @@ impl ImageLayerWriterInner {
         self,
         ctx: &RequestContext,
         end_key: Option<Key>,
-    ) -> anyhow::Result<(PersistentLayerDesc, Utf8PathBuf)> {
-        let temp_path = self.path.clone();
-        let result = self.finish0(ctx, end_key).await;
-        if let Err(ref e) = result {
-            tracing::info!(%temp_path, "cleaning up temporary file after error during writing: {e}");
-            if let Err(e) = std::fs::remove_file(&temp_path) {
-                tracing::warn!(error=%e, %temp_path, "error cleaning up temporary layer file after error during writing");
-            }
-        }
-        result
-    }
-
-    ///
-    /// Finish writing the image layer.
-    ///
-    async fn finish0(
-        self,
-        ctx: &RequestContext,
-        end_key: Option<Key>,
     ) -> anyhow::Result<(PersistentLayerDesc, Utf8PathBuf)> {
         let index_start_blk = self.blob_writer.size().div_ceil(PAGE_SZ as u64) as u32;
 
@@ -932,15 +942,24 @@ impl ImageLayerWriterInner {
             crate::metrics::COMPRESSION_IMAGE_OUTPUT_BYTES.inc_by(compressed_size);
         };
 
-        let mut file = self.blob_writer.into_inner();
+        let file = self
+            .blob_writer
+            .shutdown(
+                BufferedWriterShutdownMode::ZeroPadToNextMultiple(PAGE_SZ),
+                ctx,
+            )
+            .await?;
 
         // Write out the index
-        file.seek(SeekFrom::Start(index_start_blk as u64 * PAGE_SZ as u64))
-            .await?;
+        let mut offset = index_start_blk as u64 * PAGE_SZ as u64;
         let (index_root_blk, block_buf) = self.tree.finish()?;
+
+        // TODO(yuchen): https://github.com/neondatabase/neon/issues/10092
+        // Should we just replace BlockBuf::blocks with one big buffer?
         for buf in block_buf.blocks {
-            let (_buf, res) = file.write_all(buf.slice_len(), ctx).await;
+            let (_buf, res) = file.write_all_at(buf.slice_len(), offset, ctx).await;
             res?;
+            offset += PAGE_SZ as u64;
         }
 
         let final_key_range = if let Some(end_key) = end_key {
@@ -961,11 +980,9 @@ impl ImageLayerWriterInner {
             index_root_blk,
         };
 
-        let mut buf = Vec::with_capacity(PAGE_SZ);
-        // TODO: could use smallvec here but it's a pain with Slice<T>
-        Summary::ser_into(&summary, &mut buf)?;
-        file.seek(SeekFrom::Start(0)).await?;
-        let (_buf, res) = file.write_all(buf.slice_len(), ctx).await;
+        // Writes summary at the first block (offset 0).
+        let buf = summary.ser_into_page()?;
+        let (_buf, res) = file.write_all_at(buf.slice_len(), 0, ctx).await;
         res?;
 
         let metadata = file
@@ -1000,6 +1017,10 @@ impl ImageLayerWriterInner {
 
         trace!("created image layer {}", self.path);
 
+        // The gate guard stored in `destination_file` is dropped. Callers (e.g.. flush loop or compaction)
+        // keep the gate open also, so that it's safe for them to rename the file to its final destination.
+        file.disarm_into_inner();
+
         Ok((desc, self.path))
     }
 }
@@ -1125,14 +1146,6 @@ impl ImageLayerWriter {
     }
 }
 
-impl Drop for ImageLayerWriter {
-    fn drop(&mut self) {
-        if let Some(inner) = self.inner.take() {
-            inner.blob_writer.into_inner().remove();
-        }
-    }
-}
-
 pub struct ImageLayerIterator<'a> {
     image_layer: &'a ImageLayerInner,
     ctx: &'a RequestContext,
diff --git a/pageserver/src/tenant/storage_layer/merge_iterator.rs b/pageserver/src/tenant/storage_layer/merge_iterator.rs
index 55db9fe06a..e084e3d567 100644
--- a/pageserver/src/tenant/storage_layer/merge_iterator.rs
+++ b/pageserver/src/tenant/storage_layer/merge_iterator.rs
@@ -19,6 +19,7 @@ pub(crate) enum LayerRef<'a> {
 }
 
 impl<'a> LayerRef<'a> {
+    #[allow(dead_code)]
     fn iter(self, ctx: &'a RequestContext) -> LayerIterRef<'a> {
         match self {
             Self::Image(x) => LayerIterRef::Image(x.iter(ctx)),
@@ -26,6 +27,22 @@ impl<'a> LayerRef<'a> {
         }
     }
 
+    fn iter_with_options(
+        self,
+        ctx: &'a RequestContext,
+        max_read_size: u64,
+        max_batch_size: usize,
+    ) -> LayerIterRef<'a> {
+        match self {
+            Self::Image(x) => {
+                LayerIterRef::Image(x.iter_with_options(ctx, max_read_size, max_batch_size))
+            }
+            Self::Delta(x) => {
+                LayerIterRef::Delta(x.iter_with_options(ctx, max_read_size, max_batch_size))
+            }
+        }
+    }
+
     fn layer_dbg_info(&self) -> String {
         match self {
             Self::Image(x) => x.layer_dbg_info(),
@@ -66,6 +83,8 @@ pub(crate) enum IteratorWrapper<'a> {
         first_key_lower_bound: (Key, Lsn),
         layer: LayerRef<'a>,
         source_desc: Arc<PersistentLayerKey>,
+        max_read_size: u64,
+        max_batch_size: usize,
     },
     Loaded {
         iter: PeekableLayerIterRef<'a>,
@@ -146,6 +165,8 @@ impl<'a> IteratorWrapper<'a> {
     pub fn create_from_image_layer(
         image_layer: &'a ImageLayerInner,
         ctx: &'a RequestContext,
+        max_read_size: u64,
+        max_batch_size: usize,
     ) -> Self {
         Self::NotLoaded {
             layer: LayerRef::Image(image_layer),
@@ -157,12 +178,16 @@ impl<'a> IteratorWrapper<'a> {
                 is_delta: false,
             }
             .into(),
+            max_read_size,
+            max_batch_size,
         }
     }
 
     pub fn create_from_delta_layer(
         delta_layer: &'a DeltaLayerInner,
         ctx: &'a RequestContext,
+        max_read_size: u64,
+        max_batch_size: usize,
     ) -> Self {
         Self::NotLoaded {
             layer: LayerRef::Delta(delta_layer),
@@ -174,6 +199,8 @@ impl<'a> IteratorWrapper<'a> {
                 is_delta: true,
             }
             .into(),
+            max_read_size,
+            max_batch_size,
         }
     }
 
@@ -204,11 +231,13 @@ impl<'a> IteratorWrapper<'a> {
             first_key_lower_bound,
             layer,
             source_desc,
+            max_read_size,
+            max_batch_size,
         } = self
         else {
             unreachable!()
         };
-        let iter = layer.iter(ctx);
+        let iter = layer.iter_with_options(ctx, *max_read_size, *max_batch_size);
         let iter = PeekableLayerIterRef::create(iter).await?;
         if let Some((k1, l1, _)) = iter.peek() {
             let (k2, l2) = first_key_lower_bound;
@@ -293,21 +322,41 @@ impl MergeIteratorItem for ((Key, Lsn, Value), Arc<PersistentLayerKey>) {
 }
 
 impl<'a> MergeIterator<'a> {
+    pub fn create_with_options(
+        deltas: &[&'a DeltaLayerInner],
+        images: &[&'a ImageLayerInner],
+        ctx: &'a RequestContext,
+        max_read_size: u64,
+        max_batch_size: usize,
+    ) -> Self {
+        let mut heap = Vec::with_capacity(images.len() + deltas.len());
+        for image in images {
+            heap.push(IteratorWrapper::create_from_image_layer(
+                image,
+                ctx,
+                max_read_size,
+                max_batch_size,
+            ));
+        }
+        for delta in deltas {
+            heap.push(IteratorWrapper::create_from_delta_layer(
+                delta,
+                ctx,
+                max_read_size,
+                max_batch_size,
+            ));
+        }
+        Self {
+            heap: BinaryHeap::from(heap),
+        }
+    }
+
     pub fn create(
         deltas: &[&'a DeltaLayerInner],
         images: &[&'a ImageLayerInner],
         ctx: &'a RequestContext,
     ) -> Self {
-        let mut heap = Vec::with_capacity(images.len() + deltas.len());
-        for image in images {
-            heap.push(IteratorWrapper::create_from_image_layer(image, ctx));
-        }
-        for delta in deltas {
-            heap.push(IteratorWrapper::create_from_delta_layer(delta, ctx));
-        }
-        Self {
-            heap: BinaryHeap::from(heap),
-        }
+        Self::create_with_options(deltas, images, ctx, 1024 * 8192, 1024)
     }
 
     pub(crate) async fn next_inner<R: MergeIteratorItem>(&mut self) -> anyhow::Result<Option<R>> {
diff --git a/pageserver/src/tenant/timeline/compaction.rs b/pageserver/src/tenant/timeline/compaction.rs
index 47a07f929d..9086d29d50 100644
--- a/pageserver/src/tenant/timeline/compaction.rs
+++ b/pageserver/src/tenant/timeline/compaction.rs
@@ -2828,6 +2828,41 @@ impl Timeline {
         Ok(())
     }
 
+    /// Check if the memory usage is within the limit.
+    async fn check_memory_usage(
+        self: &Arc<Self>,
+        layer_selection: &[Layer],
+    ) -> Result<(), CompactionError> {
+        let mut estimated_memory_usage_mb = 0.0;
+        let mut num_image_layers = 0;
+        let mut num_delta_layers = 0;
+        let target_layer_size_bytes = 256 * 1024 * 1024;
+        for layer in layer_selection {
+            let layer_desc = layer.layer_desc();
+            if layer_desc.is_delta() {
+                // Delta layers at most have 1MB buffer; 3x to make it safe (there're deltas as large as 16KB).
+                // Multiply the layer size so that tests can pass.
+                estimated_memory_usage_mb +=
+                    3.0 * (layer_desc.file_size / target_layer_size_bytes) as f64;
+                num_delta_layers += 1;
+            } else {
+                // Image layers at most have 1MB buffer but it might be compressed; assume 5x compression ratio.
+                estimated_memory_usage_mb +=
+                    5.0 * (layer_desc.file_size / target_layer_size_bytes) as f64;
+                num_image_layers += 1;
+            }
+        }
+        if estimated_memory_usage_mb > 1024.0 {
+            return Err(CompactionError::Other(anyhow!(
+                "estimated memory usage is too high: {}MB, giving up compaction; num_image_layers={}, num_delta_layers={}",
+                estimated_memory_usage_mb,
+                num_image_layers,
+                num_delta_layers
+            )));
+        }
+        Ok(())
+    }
+
     /// Get a watermark for gc-compaction, that is the lowest LSN that we can use as the `gc_horizon` for
     /// the compaction algorithm. It is min(space_cutoff, time_cutoff, latest_gc_cutoff, standby_horizon).
     /// Leases and retain_lsns are considered in the gc-compaction job itself so we don't need to account for them
@@ -3264,6 +3299,17 @@ impl Timeline {
         self.check_compaction_space(&job_desc.selected_layers)
             .await?;
 
+        self.check_memory_usage(&job_desc.selected_layers).await?;
+        if job_desc.selected_layers.len() > 100
+            && job_desc.rewrite_layers.len() as f64 >= job_desc.selected_layers.len() as f64 * 0.7
+        {
+            return Err(CompactionError::Other(anyhow!(
+                "too many layers to rewrite: {} / {}, giving up compaction",
+                job_desc.rewrite_layers.len(),
+                job_desc.selected_layers.len()
+            )));
+        }
+
         // Generate statistics for the compaction
         for layer in &job_desc.selected_layers {
             let desc = layer.layer_desc();
@@ -3359,7 +3405,13 @@ impl Timeline {
             .context("failed to collect gc compaction keyspace")
             .map_err(CompactionError::Other)?;
         let mut merge_iter = FilterIterator::create(
-            MergeIterator::create(&delta_layers, &image_layers, ctx),
+            MergeIterator::create_with_options(
+                &delta_layers,
+                &image_layers,
+                ctx,
+                128 * 8192, /* 1MB buffer for each of the inner iterators */
+                128,
+            ),
             dense_ks,
             sparse_ks,
         )
diff --git a/pageserver/src/tenant/timeline/import_pgdata.rs b/pageserver/src/tenant/timeline/import_pgdata.rs
index 8b94a114d6..b917fdbfd8 100644
--- a/pageserver/src/tenant/timeline/import_pgdata.rs
+++ b/pageserver/src/tenant/timeline/import_pgdata.rs
@@ -1,20 +1,21 @@
 use std::sync::Arc;
 
 use anyhow::{Context, bail};
+use pageserver_api::models::ShardImportStatus;
 use remote_storage::RemotePath;
 use tokio_util::sync::CancellationToken;
-use tracing::{Instrument, info, info_span};
+use tracing::info;
 use utils::lsn::Lsn;
 
 use super::Timeline;
 use crate::context::RequestContext;
+use crate::controller_upcall_client::{StorageControllerUpcallApi, StorageControllerUpcallClient};
 use crate::tenant::metadata::TimelineMetadata;
 
 mod flow;
 mod importbucket_client;
 mod importbucket_format;
 pub(crate) mod index_part_format;
-pub(crate) mod upcall_api;
 
 pub async fn doit(
     timeline: &Arc<Timeline>,
@@ -34,23 +35,6 @@ pub async fn doit(
 
     let storage = importbucket_client::new(timeline.conf, &location, cancel.clone()).await?;
 
-    info!("get spec early so we know we'll be able to upcall when done");
-    let Some(spec) = storage.get_spec().await? else {
-        bail!("spec not found")
-    };
-
-    let upcall_client =
-        upcall_api::Client::new(timeline.conf, cancel.clone()).context("create upcall client")?;
-
-    //
-    // send an early progress update to clean up k8s job early and generate potentially useful logs
-    //
-    info!("send early progress update");
-    upcall_client
-        .send_progress_until_success(&spec)
-        .instrument(info_span!("early_progress_update"))
-        .await?;
-
     let status_prefix = RemotePath::from_string("status").unwrap();
 
     //
@@ -176,7 +160,21 @@ pub async fn doit(
 
         //
         // Communicate that shard is done.
+        // Ensure at-least-once delivery of the upcall to storage controller
+        // before we mark the task as done and never come here again.
         //
+        let storcon_client = StorageControllerUpcallClient::new(timeline.conf, &cancel)?
+            .expect("storcon configured");
+        storcon_client
+            .put_timeline_import_status(
+                timeline.tenant_shard_id,
+                timeline.timeline_id,
+                // TODO(vlad): What about import errors?
+                ShardImportStatus::Done,
+            )
+            .await
+            .map_err(|_err| anyhow::anyhow!("Shut down while putting timeline import status"))?;
+
         storage
             .put_json(
                 &shard_status_key,
@@ -186,16 +184,6 @@ pub async fn doit(
             .context("put shard status")?;
     }
 
-    //
-    // Ensure at-least-once deliver of the upcall to cplane
-    // before we mark the task as done and never come here again.
-    //
-    info!("send final progress update");
-    upcall_client
-        .send_progress_until_success(&spec)
-        .instrument(info_span!("final_progress_update"))
-        .await?;
-
     //
     // Mark as done in index_part.
     // This makes subsequent timeline loads enter the normal load code path
diff --git a/pageserver/src/tenant/timeline/import_pgdata/importbucket_client.rs b/pageserver/src/tenant/timeline/import_pgdata/importbucket_client.rs
index a17a10d56b..e7aa8f6038 100644
--- a/pageserver/src/tenant/timeline/import_pgdata/importbucket_client.rs
+++ b/pageserver/src/tenant/timeline/import_pgdata/importbucket_client.rs
@@ -13,7 +13,7 @@ use tokio_util::sync::CancellationToken;
 use tracing::{debug, info, instrument};
 use utils::lsn::Lsn;
 
-use super::{importbucket_format, index_part_format};
+use super::index_part_format;
 use crate::assert_u64_eq_usize::U64IsUsize;
 use crate::config::PageServerConf;
 
@@ -173,12 +173,6 @@ impl RemoteStorageWrapper {
         res
     }
 
-    pub async fn get_spec(&self) -> Result<Option<importbucket_format::Spec>, anyhow::Error> {
-        self.get_json(&RemotePath::from_string("spec.json").unwrap())
-            .await
-            .context("get spec")
-    }
-
     #[instrument(level = tracing::Level::DEBUG, skip_all, fields(%path))]
     pub async fn get_json<T: DeserializeOwned>(
         &self,
@@ -244,7 +238,8 @@ impl RemoteStorageWrapper {
                             kind: DownloadKind::Large,
                             etag: None,
                             byte_start: Bound::Included(start_inclusive),
-                            byte_end: Bound::Excluded(end_exclusive)
+                            byte_end: Bound::Excluded(end_exclusive),
+                            version_id: None,
                         },
                         &self.cancel)
                     .await?;
diff --git a/pageserver/src/tenant/timeline/import_pgdata/importbucket_format.rs b/pageserver/src/tenant/timeline/import_pgdata/importbucket_format.rs
index 04ba3c6f1f..57c647cc7f 100644
--- a/pageserver/src/tenant/timeline/import_pgdata/importbucket_format.rs
+++ b/pageserver/src/tenant/timeline/import_pgdata/importbucket_format.rs
@@ -11,10 +11,3 @@ pub struct ShardStatus {
     pub done: bool,
     // TODO: remaining fields
 }
-
-// TODO: dedupe with fast_import code
-#[derive(Deserialize, Serialize, Debug, Clone, PartialEq, Eq)]
-pub struct Spec {
-    pub project_id: String,
-    pub branch_id: String,
-}
diff --git a/pageserver/src/tenant/timeline/import_pgdata/upcall_api.rs b/pageserver/src/tenant/timeline/import_pgdata/upcall_api.rs
deleted file mode 100644
index 99081a65e0..0000000000
--- a/pageserver/src/tenant/timeline/import_pgdata/upcall_api.rs
+++ /dev/null
@@ -1,124 +0,0 @@
-//! FIXME: most of this is copy-paste from mgmt_api.rs ; dedupe into a `reqwest_utils::Client` crate.
-use pageserver_client::mgmt_api::{Error, ResponseErrorMessageExt};
-use reqwest::{Certificate, Method};
-use serde::{Deserialize, Serialize};
-use tokio_util::sync::CancellationToken;
-use tracing::error;
-
-use super::importbucket_format::Spec;
-use crate::config::PageServerConf;
-
-pub struct Client {
-    base_url: String,
-    authorization_header: Option<String>,
-    client: reqwest::Client,
-    cancel: CancellationToken,
-}
-
-pub type Result<T> = std::result::Result<T, Error>;
-
-#[derive(Serialize, Deserialize, Debug)]
-struct ImportProgressRequest {
-    // no fields yet, not sure if there every will be any
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-struct ImportProgressResponse {
-    // we don't care
-}
-
-impl Client {
-    pub fn new(conf: &PageServerConf, cancel: CancellationToken) -> anyhow::Result<Self> {
-        let Some(ref base_url) = conf.import_pgdata_upcall_api else {
-            anyhow::bail!("import_pgdata_upcall_api is not configured")
-        };
-        let mut http_client = reqwest::Client::builder();
-        for cert in &conf.ssl_ca_certs {
-            http_client = http_client.add_root_certificate(Certificate::from_der(cert.contents())?);
-        }
-        let http_client = http_client.build()?;
-
-        Ok(Self {
-            base_url: base_url.to_string(),
-            client: http_client,
-            cancel,
-            authorization_header: conf
-                .import_pgdata_upcall_api_token
-                .as_ref()
-                .map(|secret_string| secret_string.get_contents())
-                .map(|jwt| format!("Bearer {jwt}")),
-        })
-    }
-
-    fn start_request<U: reqwest::IntoUrl>(
-        &self,
-        method: Method,
-        uri: U,
-    ) -> reqwest::RequestBuilder {
-        let req = self.client.request(method, uri);
-        if let Some(value) = &self.authorization_header {
-            req.header(reqwest::header::AUTHORIZATION, value)
-        } else {
-            req
-        }
-    }
-
-    async fn request_noerror<B: serde::Serialize, U: reqwest::IntoUrl>(
-        &self,
-        method: Method,
-        uri: U,
-        body: B,
-    ) -> Result<reqwest::Response> {
-        self.start_request(method, uri)
-            .json(&body)
-            .send()
-            .await
-            .map_err(Error::ReceiveBody)
-    }
-
-    async fn request<B: serde::Serialize, U: reqwest::IntoUrl>(
-        &self,
-        method: Method,
-        uri: U,
-        body: B,
-    ) -> Result<reqwest::Response> {
-        let res = self.request_noerror(method, uri, body).await?;
-        let response = res.error_from_body().await?;
-        Ok(response)
-    }
-
-    pub async fn send_progress_once(&self, spec: &Spec) -> Result<()> {
-        let url = format!(
-            "{}/projects/{}/branches/{}/import_progress",
-            self.base_url, spec.project_id, spec.branch_id
-        );
-        let ImportProgressResponse {} = self
-            .request(Method::POST, url, &ImportProgressRequest {})
-            .await?
-            .json()
-            .await
-            .map_err(Error::ReceiveBody)?;
-        Ok(())
-    }
-
-    pub async fn send_progress_until_success(&self, spec: &Spec) -> anyhow::Result<()> {
-        loop {
-            match self.send_progress_once(spec).await {
-                Ok(()) => return Ok(()),
-                Err(Error::Cancelled) => return Err(anyhow::anyhow!("cancelled")),
-                Err(err) => {
-                    error!(?err, "error sending progress, retrying");
-                    if tokio::time::timeout(
-                        std::time::Duration::from_secs(10),
-                        self.cancel.cancelled(),
-                    )
-                    .await
-                    .is_ok()
-                    {
-                        anyhow::bail!("cancelled while sending early progress update");
-                    }
-                }
-            }
-        }
-    }
-}
diff --git a/pageserver/src/tenant/vectored_blob_io.rs b/pageserver/src/tenant/vectored_blob_io.rs
index f9a44fe4ca..c9fdefaf66 100644
--- a/pageserver/src/tenant/vectored_blob_io.rs
+++ b/pageserver/src/tenant/vectored_blob_io.rs
@@ -507,7 +507,9 @@ impl<'a> VectoredBlobReader<'a> {
 
         for (blob_start, meta) in blobs_at.iter().copied() {
             let header_start = (blob_start - read.start) as usize;
-            let header = Header::decode(&buf[header_start..])?;
+            let header = Header::decode(&buf[header_start..]).map_err(|anyhow_err| {
+                std::io::Error::new(std::io::ErrorKind::InvalidData, anyhow_err)
+            })?;
             let data_start = header_start + header.header_len;
             let end = data_start + header.data_len;
             let compression_bits = header.compression_bits;
@@ -662,7 +664,6 @@ impl StreamingVectoredReadPlanner {
 
 #[cfg(test)]
 mod tests {
-    use anyhow::Error;
 
     use super::super::blob_io::tests::{random_array, write_maybe_compressed};
     use super::*;
@@ -945,13 +946,16 @@ mod tests {
         }
     }
 
-    async fn round_trip_test_compressed(blobs: &[Vec<u8>], compression: bool) -> Result<(), Error> {
+    async fn round_trip_test_compressed(
+        blobs: &[Vec<u8>],
+        compression: bool,
+    ) -> anyhow::Result<()> {
         let ctx =
             RequestContext::new(TaskKind::UnitTest, DownloadBehavior::Error).with_scope_unit_test();
         let (_temp_dir, pathbuf, offsets) =
-            write_maybe_compressed::<true>(blobs, compression, &ctx).await?;
+            write_maybe_compressed(blobs, compression, &ctx).await?;
 
-        let file = VirtualFile::open(&pathbuf, &ctx).await?;
+        let file = VirtualFile::open_v2(&pathbuf, &ctx).await?;
         let file_len = std::fs::metadata(&pathbuf)?.len();
 
         // Multiply by two (compressed data might need more space), and add a few bytes for the header
@@ -997,7 +1001,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_really_big_array() -> Result<(), Error> {
+    async fn test_really_big_array() -> anyhow::Result<()> {
         let blobs = &[
             b"test".to_vec(),
             random_array(10 * PAGE_SZ),
@@ -1012,7 +1016,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_arrays_inc() -> Result<(), Error> {
+    async fn test_arrays_inc() -> anyhow::Result<()> {
         let blobs = (0..PAGE_SZ / 8)
             .map(|v| random_array(v * 16))
             .collect::<Vec<_>>();
diff --git a/pageserver/src/virtual_file.rs b/pageserver/src/virtual_file.rs
index 45cd0f469b..58953407b1 100644
--- a/pageserver/src/virtual_file.rs
+++ b/pageserver/src/virtual_file.rs
@@ -12,10 +12,11 @@
 //! src/backend/storage/file/fd.c
 //!
 use std::fs::File;
-use std::io::{Error, ErrorKind, Seek, SeekFrom};
+use std::io::{Error, ErrorKind};
 use std::os::fd::{AsRawFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
 #[cfg(target_os = "linux")]
 use std::os::unix::fs::OpenOptionsExt;
+use std::sync::LazyLock;
 use std::sync::atomic::{AtomicBool, AtomicU8, AtomicUsize, Ordering};
 
 use camino::{Utf8Path, Utf8PathBuf};
@@ -25,29 +26,31 @@ use owned_buffers_io::aligned_buffer::{AlignedBufferMut, AlignedSlice, ConstAlig
 use owned_buffers_io::io_buf_aligned::{IoBufAligned, IoBufAlignedMut};
 use owned_buffers_io::io_buf_ext::FullSlice;
 use pageserver_api::config::defaults::DEFAULT_IO_BUFFER_ALIGNMENT;
-pub use pageserver_api::models::virtual_file as api;
 use tokio::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard};
 use tokio::time::Instant;
 use tokio_epoll_uring::{BoundedBuf, IoBuf, IoBufMut, Slice};
 
+use self::owned_buffers_io::write::OwnedAsyncWriter;
 use crate::assert_u64_eq_usize::UsizeIsU64;
 use crate::context::RequestContext;
 use crate::metrics::{STORAGE_IO_TIME_METRIC, StorageIoOperation};
 use crate::page_cache::{PAGE_SZ, PageWriteGuard};
-pub(crate) mod io_engine;
+
+pub(crate) use api::IoMode;
+pub(crate) use io_engine::IoEngineKind;
 pub use io_engine::{
     FeatureTestResult as IoEngineFeatureTestResult, feature_test as io_engine_feature_test,
     io_engine_for_bench,
 };
-mod metadata;
-mod open_options;
-pub(crate) use api::IoMode;
-pub(crate) use io_engine::IoEngineKind;
 pub(crate) use metadata::Metadata;
 pub(crate) use open_options::*;
+pub use pageserver_api::models::virtual_file as api;
+pub use temporary::TempVirtualFile;
 
-use self::owned_buffers_io::write::OwnedAsyncWriter;
-
+pub(crate) mod io_engine;
+mod metadata;
+mod open_options;
+mod temporary;
 pub(crate) mod owned_buffers_io {
     //! Abstractions for IO with owned buffers.
     //!
@@ -94,69 +97,38 @@ impl VirtualFile {
         Self::open_with_options_v2(path.as_ref(), OpenOptions::new().read(true), ctx).await
     }
 
-    pub async fn create<P: AsRef<Utf8Path>>(
-        path: P,
-        ctx: &RequestContext,
-    ) -> Result<Self, std::io::Error> {
-        let inner = VirtualFileInner::create(path, ctx).await?;
-        Ok(VirtualFile {
-            inner,
-            _mode: IoMode::Buffered,
-        })
-    }
-
-    pub async fn create_v2<P: AsRef<Utf8Path>>(
-        path: P,
-        ctx: &RequestContext,
-    ) -> Result<Self, std::io::Error> {
-        VirtualFile::open_with_options_v2(
-            path.as_ref(),
-            OpenOptions::new().write(true).create(true).truncate(true),
-            ctx,
-        )
-        .await
-    }
-
-    pub async fn open_with_options<P: AsRef<Utf8Path>>(
-        path: P,
-        open_options: &OpenOptions,
-        ctx: &RequestContext,
-    ) -> Result<Self, std::io::Error> {
-        let inner = VirtualFileInner::open_with_options(path, open_options, ctx).await?;
-        Ok(VirtualFile {
-            inner,
-            _mode: IoMode::Buffered,
-        })
-    }
-
     pub async fn open_with_options_v2<P: AsRef<Utf8Path>>(
         path: P,
         open_options: &OpenOptions,
         ctx: &RequestContext,
     ) -> Result<Self, std::io::Error> {
-        let file = match get_io_mode() {
-            IoMode::Buffered => {
-                let inner = VirtualFileInner::open_with_options(path, open_options, ctx).await?;
-                VirtualFile {
-                    inner,
-                    _mode: IoMode::Buffered,
-                }
-            }
+        let mode = get_io_mode();
+        let set_o_direct = match (mode, open_options.is_write()) {
+            (IoMode::Buffered, _) => false,
             #[cfg(target_os = "linux")]
-            IoMode::Direct => {
-                let inner = VirtualFileInner::open_with_options(
-                    path,
-                    open_options.clone().custom_flags(nix::libc::O_DIRECT),
-                    ctx,
-                )
-                .await?;
-                VirtualFile {
-                    inner,
-                    _mode: IoMode::Direct,
-                }
-            }
+            (IoMode::Direct, false) => true,
+            #[cfg(target_os = "linux")]
+            (IoMode::Direct, true) => false,
+            #[cfg(target_os = "linux")]
+            (IoMode::DirectRw, _) => true,
         };
-        Ok(file)
+        let open_options = open_options.clone();
+        let open_options = if set_o_direct {
+            #[cfg(target_os = "linux")]
+            {
+                let mut open_options = open_options;
+                open_options.custom_flags(nix::libc::O_DIRECT);
+                open_options
+            }
+            #[cfg(not(target_os = "linux"))]
+            unreachable!(
+                "O_DIRECT is not supported on this platform, IoMode's that result in set_o_direct=true shouldn't even be defined"
+            );
+        } else {
+            open_options
+        };
+        let inner = VirtualFileInner::open_with_options(path, open_options, ctx).await?;
+        Ok(VirtualFile { inner, _mode: mode })
     }
 
     pub fn path(&self) -> &Utf8Path {
@@ -185,18 +157,14 @@ impl VirtualFile {
         self.inner.sync_data().await
     }
 
+    pub async fn set_len(&self, len: u64, ctx: &RequestContext) -> Result<(), Error> {
+        self.inner.set_len(len, ctx).await
+    }
+
     pub async fn metadata(&self) -> Result<Metadata, Error> {
         self.inner.metadata().await
     }
 
-    pub fn remove(self) {
-        self.inner.remove();
-    }
-
-    pub async fn seek(&mut self, pos: SeekFrom) -> Result<u64, Error> {
-        self.inner.seek(pos).await
-    }
-
     pub async fn read_exact_at<Buf>(
         &self,
         slice: Slice<Buf>,
@@ -227,25 +195,31 @@ impl VirtualFile {
         self.inner.write_all_at(buf, offset, ctx).await
     }
 
-    pub async fn write_all<Buf: IoBuf + Send>(
-        &mut self,
-        buf: FullSlice<Buf>,
+    pub(crate) async fn read_to_string<P: AsRef<Utf8Path>>(
+        path: P,
         ctx: &RequestContext,
-    ) -> (FullSlice<Buf>, Result<usize, Error>) {
-        self.inner.write_all(buf, ctx).await
-    }
-
-    async fn read_to_end(&mut self, buf: &mut Vec<u8>, ctx: &RequestContext) -> Result<(), Error> {
-        self.inner.read_to_end(buf, ctx).await
-    }
-
-    pub(crate) async fn read_to_string(
-        &mut self,
-        ctx: &RequestContext,
-    ) -> Result<String, anyhow::Error> {
+    ) -> std::io::Result<String> {
+        let file = VirtualFile::open(path, ctx).await?; // TODO: open_v2
         let mut buf = Vec::new();
-        self.read_to_end(&mut buf, ctx).await?;
-        Ok(String::from_utf8(buf)?)
+        let mut tmp = vec![0; 128];
+        let mut pos: u64 = 0;
+        loop {
+            let slice = tmp.slice(..128);
+            let (slice, res) = file.inner.read_at(slice, pos, ctx).await;
+            match res {
+                Ok(0) => break,
+                Ok(n) => {
+                    pos += n as u64;
+                    buf.extend_from_slice(&slice[..n]);
+                }
+                Err(ref e) if e.kind() == std::io::ErrorKind::Interrupted => {}
+                Err(e) => return Err(e),
+            }
+            tmp = slice.into_inner();
+        }
+        String::from_utf8(buf).map_err(|_| {
+            std::io::Error::new(ErrorKind::InvalidData, "file contents are not valid UTF-8")
+        })
     }
 }
 
@@ -292,9 +266,6 @@ pub struct VirtualFileInner {
     /// belongs to a different VirtualFile.
     handle: RwLock<SlotHandle>,
 
-    /// Current file position
-    pos: u64,
-
     /// File path and options to use to open it.
     ///
     /// Note: this only contains the options needed to re-open it. For example,
@@ -559,21 +530,7 @@ impl VirtualFileInner {
         path: P,
         ctx: &RequestContext,
     ) -> Result<VirtualFileInner, std::io::Error> {
-        Self::open_with_options(path.as_ref(), OpenOptions::new().read(true), ctx).await
-    }
-
-    /// Create a new file for writing. If the file exists, it will be truncated.
-    /// Like File::create.
-    pub async fn create<P: AsRef<Utf8Path>>(
-        path: P,
-        ctx: &RequestContext,
-    ) -> Result<VirtualFileInner, std::io::Error> {
-        Self::open_with_options(
-            path.as_ref(),
-            OpenOptions::new().write(true).create(true).truncate(true),
-            ctx,
-        )
-        .await
+        Self::open_with_options(path.as_ref(), OpenOptions::new().read(true).clone(), ctx).await
     }
 
     /// Open a file with given options.
@@ -583,7 +540,7 @@ impl VirtualFileInner {
     /// on the first time. Make sure that's sane!
     pub async fn open_with_options<P: AsRef<Utf8Path>>(
         path: P,
-        open_options: &OpenOptions,
+        open_options: OpenOptions,
         _ctx: &RequestContext,
     ) -> Result<VirtualFileInner, std::io::Error> {
         let path = path.as_ref();
@@ -608,7 +565,6 @@ impl VirtualFileInner {
 
         let vfile = VirtualFileInner {
             handle: RwLock::new(handle),
-            pos: 0,
             path: path.to_owned(),
             open_options: reopen_options,
         };
@@ -675,6 +631,13 @@ impl VirtualFileInner {
         })
     }
 
+    pub async fn set_len(&self, len: u64, _ctx: &RequestContext) -> Result<(), Error> {
+        with_file!(self, StorageIoOperation::SetLen, |file_guard| {
+            let (_file_guard, res) = io_engine::get().set_len(file_guard, len).await;
+            res.maybe_fatal_err("set_len")
+        })
+    }
+
     /// Helper function internal to `VirtualFile` that looks up the underlying File,
     /// opens it and evicts some other File if necessary. The passed parameter is
     /// assumed to be a function available for the physical `File`.
@@ -742,38 +705,6 @@ impl VirtualFileInner {
         })
     }
 
-    pub fn remove(self) {
-        let path = self.path.clone();
-        drop(self);
-        std::fs::remove_file(path).expect("failed to remove the virtual file");
-    }
-
-    pub async fn seek(&mut self, pos: SeekFrom) -> Result<u64, Error> {
-        match pos {
-            SeekFrom::Start(offset) => {
-                self.pos = offset;
-            }
-            SeekFrom::End(offset) => {
-                self.pos = with_file!(self, StorageIoOperation::Seek, |mut file_guard| file_guard
-                    .with_std_file_mut(|std_file| std_file.seek(SeekFrom::End(offset))))?
-            }
-            SeekFrom::Current(offset) => {
-                let pos = self.pos as i128 + offset as i128;
-                if pos < 0 {
-                    return Err(Error::new(
-                        ErrorKind::InvalidInput,
-                        "offset would be negative",
-                    ));
-                }
-                if pos > u64::MAX as i128 {
-                    return Err(Error::new(ErrorKind::InvalidInput, "offset overflow"));
-                }
-                self.pos = pos as u64;
-            }
-        }
-        Ok(self.pos)
-    }
-
     /// Read the file contents in range `offset..(offset + slice.bytes_total())` into `slice[0..slice.bytes_total()]`.
     ///
     /// The returned `Slice<Buf>` is equivalent to the input `slice`, i.e., it's the same view into the same buffer.
@@ -857,59 +788,7 @@ impl VirtualFileInner {
         (restore(buf), Ok(()))
     }
 
-    /// Writes `buf` to the file at the current offset.
-    ///
-    /// Panics if there is an uninitialized range in `buf`, as that is most likely a bug in the caller.
-    pub async fn write_all<Buf: IoBuf + Send>(
-        &mut self,
-        buf: FullSlice<Buf>,
-        ctx: &RequestContext,
-    ) -> (FullSlice<Buf>, Result<usize, Error>) {
-        let buf = buf.into_raw_slice();
-        let bounds = buf.bounds();
-        let restore =
-            |buf: Slice<_>| FullSlice::must_new(Slice::from_buf_bounds(buf.into_inner(), bounds));
-        let nbytes = buf.len();
-        let mut buf = buf;
-        while !buf.is_empty() {
-            let (tmp, res) = self.write(FullSlice::must_new(buf), ctx).await;
-            buf = tmp.into_raw_slice();
-            match res {
-                Ok(0) => {
-                    return (
-                        restore(buf),
-                        Err(Error::new(
-                            std::io::ErrorKind::WriteZero,
-                            "failed to write whole buffer",
-                        )),
-                    );
-                }
-                Ok(n) => {
-                    buf = buf.slice(n..);
-                }
-                Err(ref e) if e.kind() == std::io::ErrorKind::Interrupted => {}
-                Err(e) => return (restore(buf), Err(e)),
-            }
-        }
-        (restore(buf), Ok(nbytes))
-    }
-
-    async fn write<B: IoBuf + Send>(
-        &mut self,
-        buf: FullSlice<B>,
-        ctx: &RequestContext,
-    ) -> (FullSlice<B>, Result<usize, std::io::Error>) {
-        let pos = self.pos;
-        let (buf, res) = self.write_at(buf, pos, ctx).await;
-        let n = match res {
-            Ok(n) => n,
-            Err(e) => return (buf, Err(e)),
-        };
-        self.pos += n as u64;
-        (buf, Ok(n))
-    }
-
-    pub(crate) async fn read_at<Buf>(
+    pub(super) async fn read_at<Buf>(
         &self,
         buf: tokio_epoll_uring::Slice<Buf>,
         offset: u64,
@@ -937,23 +816,11 @@ impl VirtualFileInner {
         })
     }
 
-    /// The function aborts the process if the error is fatal.
     async fn write_at<B: IoBuf + Send>(
         &self,
         buf: FullSlice<B>,
         offset: u64,
         ctx: &RequestContext,
-    ) -> (FullSlice<B>, Result<usize, Error>) {
-        let (slice, result) = self.write_at_inner(buf, offset, ctx).await;
-        let result = result.maybe_fatal_err("write_at");
-        (slice, result)
-    }
-
-    async fn write_at_inner<B: IoBuf + Send>(
-        &self,
-        buf: FullSlice<B>,
-        offset: u64,
-        ctx: &RequestContext,
     ) -> (FullSlice<B>, Result<usize, Error>) {
         let file_guard = match self.lock_file().await {
             Ok(file_guard) => file_guard,
@@ -962,30 +829,13 @@ impl VirtualFileInner {
         observe_duration!(StorageIoOperation::Write, {
             let ((_file_guard, buf), result) =
                 io_engine::get().write_at(file_guard, offset, buf).await;
+            let result = result.maybe_fatal_err("write_at");
             if let Ok(size) = result {
                 ctx.io_size_metrics().write.add(size.into_u64());
             }
             (buf, result)
         })
     }
-
-    async fn read_to_end(&mut self, buf: &mut Vec<u8>, ctx: &RequestContext) -> Result<(), Error> {
-        let mut tmp = vec![0; 128];
-        loop {
-            let slice = tmp.slice(..128);
-            let (slice, res) = self.read_at(slice, self.pos, ctx).await;
-            match res {
-                Ok(0) => return Ok(()),
-                Ok(n) => {
-                    self.pos += n as u64;
-                    buf.extend_from_slice(&slice[..n]);
-                }
-                Err(ref e) if e.kind() == std::io::ErrorKind::Interrupted => {}
-                Err(e) => return Err(e),
-            }
-            tmp = slice.into_inner();
-        }
-    }
 }
 
 // Adapted from https://doc.rust-lang.org/1.72.0/src/std/os/unix/fs.rs.html#117-135
@@ -1200,19 +1050,6 @@ impl FileGuard {
         let _ = file.into_raw_fd();
         res
     }
-    /// Soft deprecation: we'll move VirtualFile to async APIs and remove this function eventually.
-    fn with_std_file_mut<F, R>(&mut self, with: F) -> R
-    where
-        F: FnOnce(&mut File) -> R,
-    {
-        // SAFETY:
-        // - lifetime of the fd: `file` doesn't outlive the OwnedFd stored in `self`.
-        // - &mut usage below: `self` is `&mut`, hence this call is the only task/thread that has control over the underlying fd
-        let mut file = unsafe { File::from_raw_fd(self.as_ref().as_raw_fd()) };
-        let res = with(&mut file);
-        let _ = file.into_raw_fd();
-        res
-    }
 }
 
 impl tokio_epoll_uring::IoFd for FileGuard {
@@ -1302,6 +1139,9 @@ impl OwnedAsyncWriter for VirtualFile {
     ) -> (FullSlice<Buf>, std::io::Result<()>) {
         VirtualFile::write_all_at(self, buf, offset, ctx).await
     }
+    async fn set_len(&self, len: u64, ctx: &RequestContext) -> std::io::Result<()> {
+        VirtualFile::set_len(self, len, ctx).await
+    }
 }
 
 impl OpenFiles {
@@ -1366,10 +1206,9 @@ pub(crate) type IoBuffer = AlignedBuffer<ConstAlign<{ get_io_buffer_alignment()
 pub(crate) type IoPageSlice<'a> =
     AlignedSlice<'a, PAGE_SZ, ConstAlign<{ get_io_buffer_alignment() }>>;
 
-static IO_MODE: once_cell::sync::Lazy<AtomicU8> =
-    once_cell::sync::Lazy::new(|| AtomicU8::new(IoMode::preferred() as u8));
+static IO_MODE: LazyLock<AtomicU8> = LazyLock::new(|| AtomicU8::new(IoMode::preferred() as u8));
 
-pub(crate) fn set_io_mode(mode: IoMode) {
+pub fn set_io_mode(mode: IoMode) {
     IO_MODE.store(mode as u8, std::sync::atomic::Ordering::Relaxed);
 }
 
@@ -1381,7 +1220,6 @@ static SYNC_MODE: AtomicU8 = AtomicU8::new(SyncMode::Sync as u8);
 
 #[cfg(test)]
 mod tests {
-    use std::io::Write;
     use std::os::unix::fs::FileExt;
     use std::sync::Arc;
 
@@ -1434,43 +1272,6 @@ mod tests {
                 MaybeVirtualFile::File(file) => file.write_all_at(&buf[..], offset),
             }
         }
-        async fn seek(&mut self, pos: SeekFrom) -> Result<u64, Error> {
-            match self {
-                MaybeVirtualFile::VirtualFile(file) => file.seek(pos).await,
-                MaybeVirtualFile::File(file) => file.seek(pos),
-            }
-        }
-        async fn write_all<Buf: IoBuf + Send>(
-            &mut self,
-            buf: FullSlice<Buf>,
-            ctx: &RequestContext,
-        ) -> Result<(), Error> {
-            match self {
-                MaybeVirtualFile::VirtualFile(file) => {
-                    let (_buf, res) = file.write_all(buf, ctx).await;
-                    res.map(|_| ())
-                }
-                MaybeVirtualFile::File(file) => file.write_all(&buf[..]),
-            }
-        }
-
-        // Helper function to slurp contents of a file, starting at the current position,
-        // into a string
-        async fn read_string(&mut self, ctx: &RequestContext) -> Result<String, Error> {
-            use std::io::Read;
-            let mut buf = String::new();
-            match self {
-                MaybeVirtualFile::VirtualFile(file) => {
-                    let mut buf = Vec::new();
-                    file.read_to_end(&mut buf, ctx).await?;
-                    return Ok(String::from_utf8(buf).unwrap());
-                }
-                MaybeVirtualFile::File(file) => {
-                    file.read_to_string(&mut buf)?;
-                }
-            }
-            Ok(buf)
-        }
 
         // Helper function to slurp a portion of a file into a string
         async fn read_string_at(
@@ -1506,7 +1307,7 @@ mod tests {
                 opts: OpenOptions,
                 ctx: &RequestContext,
             ) -> Result<MaybeVirtualFile, anyhow::Error> {
-                let vf = VirtualFile::open_with_options(&path, &opts, ctx).await?;
+                let vf = VirtualFile::open_with_options_v2(&path, &opts, ctx).await?;
                 Ok(MaybeVirtualFile::VirtualFile(vf))
             }
         }
@@ -1566,48 +1367,23 @@ mod tests {
         .await?;
 
         file_a
-            .write_all(b"foobar".to_vec().slice_len(), &ctx)
+            .write_all_at(IoBuffer::from(b"foobar").slice_len(), 0, &ctx)
             .await?;
 
         // cannot read from a file opened in write-only mode
-        let _ = file_a.read_string(&ctx).await.unwrap_err();
+        let _ = file_a.read_string_at(0, 1, &ctx).await.unwrap_err();
 
         // Close the file and re-open for reading
         let mut file_a = A::open(path_a, OpenOptions::new().read(true).to_owned(), &ctx).await?;
 
         // cannot write to a file opened in read-only mode
         let _ = file_a
-            .write_all(b"bar".to_vec().slice_len(), &ctx)
+            .write_all_at(IoBuffer::from(b"bar").slice_len(), 0, &ctx)
             .await
             .unwrap_err();
 
         // Try simple read
-        assert_eq!("foobar", file_a.read_string(&ctx).await?);
-
-        // It's positioned at the EOF now.
-        assert_eq!("", file_a.read_string(&ctx).await?);
-
-        // Test seeks.
-        assert_eq!(file_a.seek(SeekFrom::Start(1)).await?, 1);
-        assert_eq!("oobar", file_a.read_string(&ctx).await?);
-
-        assert_eq!(file_a.seek(SeekFrom::End(-2)).await?, 4);
-        assert_eq!("ar", file_a.read_string(&ctx).await?);
-
-        assert_eq!(file_a.seek(SeekFrom::Start(1)).await?, 1);
-        assert_eq!(file_a.seek(SeekFrom::Current(2)).await?, 3);
-        assert_eq!("bar", file_a.read_string(&ctx).await?);
-
-        assert_eq!(file_a.seek(SeekFrom::Current(-5)).await?, 1);
-        assert_eq!("oobar", file_a.read_string(&ctx).await?);
-
-        // Test erroneous seeks to before byte 0
-        file_a.seek(SeekFrom::End(-7)).await.unwrap_err();
-        assert_eq!(file_a.seek(SeekFrom::Start(1)).await?, 1);
-        file_a.seek(SeekFrom::Current(-2)).await.unwrap_err();
-
-        // the erroneous seek should have left the position unchanged
-        assert_eq!("oobar", file_a.read_string(&ctx).await?);
+        assert_eq!("foobar", file_a.read_string_at(0, 6, &ctx).await?);
 
         // Create another test file, and try FileExt functions on it.
         let path_b = testdir.join("file_b");
@@ -1633,9 +1409,6 @@ mod tests {
 
         // Open a lot of files, enough to cause some evictions. (Or to be precise,
         // open the same file many times. The effect is the same.)
-        //
-        // leave file_a positioned at offset 1 before we start
-        assert_eq!(file_a.seek(SeekFrom::Start(1)).await?, 1);
 
         let mut vfiles = Vec::new();
         for _ in 0..100 {
@@ -1645,7 +1418,7 @@ mod tests {
                 &ctx,
             )
             .await?;
-            assert_eq!("FOOBAR", vfile.read_string(&ctx).await?);
+            assert_eq!("FOOBAR", vfile.read_string_at(0, 6, &ctx).await?);
             vfiles.push(vfile);
         }
 
@@ -1653,8 +1426,8 @@ mod tests {
         assert!(vfiles.len() > TEST_MAX_FILE_DESCRIPTORS * 2);
 
         // The underlying file descriptor for 'file_a' should be closed now. Try to read
-        // from it again. We left the file positioned at offset 1 above.
-        assert_eq!("oobar", file_a.read_string(&ctx).await?);
+        // from it again.
+        assert_eq!("foobar", file_a.read_string_at(0, 6, &ctx).await?);
 
         // Check that all the other FDs still work too. Use them in random order for
         // good measure.
@@ -1693,7 +1466,7 @@ mod tests {
         for _ in 0..VIRTUAL_FILES {
             let f = VirtualFileInner::open_with_options(
                 &test_file_path,
-                OpenOptions::new().read(true),
+                OpenOptions::new().read(true).clone(),
                 &ctx,
             )
             .await?;
@@ -1748,7 +1521,7 @@ mod tests {
             .await
             .unwrap();
         let mut file = MaybeVirtualFile::from(VirtualFile::open(&path, &ctx).await.unwrap());
-        let post = file.read_string(&ctx).await.unwrap();
+        let post = file.read_string_at(0, 3, &ctx).await.unwrap();
         assert_eq!(post, "foo");
         assert!(!tmp_path.exists());
         drop(file);
@@ -1757,7 +1530,7 @@ mod tests {
             .await
             .unwrap();
         let mut file = MaybeVirtualFile::from(VirtualFile::open(&path, &ctx).await.unwrap());
-        let post = file.read_string(&ctx).await.unwrap();
+        let post = file.read_string_at(0, 3, &ctx).await.unwrap();
         assert_eq!(post, "bar");
         assert!(!tmp_path.exists());
         drop(file);
@@ -1782,7 +1555,7 @@ mod tests {
             .unwrap();
 
         let mut file = MaybeVirtualFile::from(VirtualFile::open(&path, &ctx).await.unwrap());
-        let post = file.read_string(&ctx).await.unwrap();
+        let post = file.read_string_at(0, 3, &ctx).await.unwrap();
         assert_eq!(post, "foo");
         assert!(!tmp_path.exists());
         drop(file);
diff --git a/pageserver/src/virtual_file/io_engine.rs b/pageserver/src/virtual_file/io_engine.rs
index 758dd6e377..dd04fb561a 100644
--- a/pageserver/src/virtual_file/io_engine.rs
+++ b/pageserver/src/virtual_file/io_engine.rs
@@ -209,6 +209,27 @@ impl IoEngine {
             }
         }
     }
+
+    pub(super) async fn set_len(
+        &self,
+        file_guard: FileGuard,
+        len: u64,
+    ) -> (FileGuard, std::io::Result<()>) {
+        match self {
+            IoEngine::NotSet => panic!("not initialized"),
+            IoEngine::StdFs => {
+                let res = file_guard.with_std_file(|std_file| std_file.set_len(len));
+                (file_guard, res)
+            }
+            #[cfg(target_os = "linux")]
+            IoEngine::TokioEpollUring => {
+                // TODO: ftruncate op for tokio-epoll-uring
+                let res = file_guard.with_std_file(|std_file| std_file.set_len(len));
+                (file_guard, res)
+            }
+        }
+    }
+
     pub(super) async fn write_at<B: IoBuf + Send>(
         &self,
         file_guard: FileGuard,
diff --git a/pageserver/src/virtual_file/open_options.rs b/pageserver/src/virtual_file/open_options.rs
index e188b8649b..7d323f3d8f 100644
--- a/pageserver/src/virtual_file/open_options.rs
+++ b/pageserver/src/virtual_file/open_options.rs
@@ -6,7 +6,12 @@ use std::path::Path;
 use super::io_engine::IoEngine;
 
 #[derive(Debug, Clone)]
-pub enum OpenOptions {
+pub struct OpenOptions {
+    write: bool,
+    inner: Inner,
+}
+#[derive(Debug, Clone)]
+enum Inner {
     StdFs(std::fs::OpenOptions),
     #[cfg(target_os = "linux")]
     TokioEpollUring(tokio_epoll_uring::ops::open_at::OpenOptions),
@@ -14,13 +19,17 @@ pub enum OpenOptions {
 
 impl Default for OpenOptions {
     fn default() -> Self {
-        match super::io_engine::get() {
+        let inner = match super::io_engine::get() {
             IoEngine::NotSet => panic!("io engine not set"),
-            IoEngine::StdFs => Self::StdFs(std::fs::OpenOptions::new()),
+            IoEngine::StdFs => Inner::StdFs(std::fs::OpenOptions::new()),
             #[cfg(target_os = "linux")]
             IoEngine::TokioEpollUring => {
-                Self::TokioEpollUring(tokio_epoll_uring::ops::open_at::OpenOptions::new())
+                Inner::TokioEpollUring(tokio_epoll_uring::ops::open_at::OpenOptions::new())
             }
+        };
+        Self {
+            write: false,
+            inner,
         }
     }
 }
@@ -30,13 +39,17 @@ impl OpenOptions {
         Self::default()
     }
 
+    pub(super) fn is_write(&self) -> bool {
+        self.write
+    }
+
     pub fn read(&mut self, read: bool) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.read(read);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.read(read);
             }
         }
@@ -44,12 +57,13 @@ impl OpenOptions {
     }
 
     pub fn write(&mut self, write: bool) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        self.write = write;
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.write(write);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.write(write);
             }
         }
@@ -57,12 +71,12 @@ impl OpenOptions {
     }
 
     pub fn create(&mut self, create: bool) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.create(create);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.create(create);
             }
         }
@@ -70,12 +84,12 @@ impl OpenOptions {
     }
 
     pub fn create_new(&mut self, create_new: bool) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.create_new(create_new);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.create_new(create_new);
             }
         }
@@ -83,12 +97,12 @@ impl OpenOptions {
     }
 
     pub fn truncate(&mut self, truncate: bool) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.truncate(truncate);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.truncate(truncate);
             }
         }
@@ -96,10 +110,10 @@ impl OpenOptions {
     }
 
     pub(in crate::virtual_file) async fn open(&self, path: &Path) -> std::io::Result<OwnedFd> {
-        match self {
-            OpenOptions::StdFs(x) => x.open(path).map(|file| file.into()),
+        match &self.inner {
+            Inner::StdFs(x) => x.open(path).map(|file| file.into()),
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let system = super::io_engine::tokio_epoll_uring_ext::thread_local_system().await;
                 system.open(path, x).await.map_err(|e| match e {
                     tokio_epoll_uring::Error::Op(e) => e,
@@ -114,12 +128,12 @@ impl OpenOptions {
 
 impl std::os::unix::prelude::OpenOptionsExt for OpenOptions {
     fn mode(&mut self, mode: u32) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.mode(mode);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.mode(mode);
             }
         }
@@ -127,12 +141,12 @@ impl std::os::unix::prelude::OpenOptionsExt for OpenOptions {
     }
 
     fn custom_flags(&mut self, flags: i32) -> &mut OpenOptions {
-        match self {
-            OpenOptions::StdFs(x) => {
+        match &mut self.inner {
+            Inner::StdFs(x) => {
                 let _ = x.custom_flags(flags);
             }
             #[cfg(target_os = "linux")]
-            OpenOptions::TokioEpollUring(x) => {
+            Inner::TokioEpollUring(x) => {
                 let _ = x.custom_flags(flags);
             }
         }
diff --git a/pageserver/src/virtual_file/owned_buffers_io/aligned_buffer/buffer_mut.rs b/pageserver/src/virtual_file/owned_buffers_io/aligned_buffer/buffer_mut.rs
index 3ee1a3c162..07f949b89e 100644
--- a/pageserver/src/virtual_file/owned_buffers_io/aligned_buffer/buffer_mut.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/aligned_buffer/buffer_mut.rs
@@ -282,6 +282,17 @@ unsafe impl<A: Alignment> tokio_epoll_uring::IoBufMut for AlignedBufferMut<A> {
     }
 }
 
+impl<A: Alignment> std::io::Write for AlignedBufferMut<A> {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        self.extend_from_slice(buf);
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        Ok(())
+    }
+}
+
 #[cfg(test)]
 mod tests {
 
diff --git a/pageserver/src/virtual_file/owned_buffers_io/write.rs b/pageserver/src/virtual_file/owned_buffers_io/write.rs
index f3ab2c285a..060834bf8c 100644
--- a/pageserver/src/virtual_file/owned_buffers_io/write.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/write.rs
@@ -1,15 +1,19 @@
 mod flush;
-use std::sync::Arc;
 
+use bytes::BufMut;
 pub(crate) use flush::FlushControl;
 use flush::FlushHandle;
 pub(crate) use flush::FlushTaskError;
+use flush::ShutdownRequest;
 use tokio_epoll_uring::IoBuf;
 use tokio_util::sync::CancellationToken;
+use tracing::trace;
 
 use super::io_buf_aligned::IoBufAligned;
+use super::io_buf_aligned::IoBufAlignedMut;
 use super::io_buf_ext::{FullSlice, IoBufExt};
 use crate::context::RequestContext;
+use crate::virtual_file::UsizeIsU64;
 use crate::virtual_file::{IoBuffer, IoBufferMut};
 
 pub(crate) trait CheapCloneForRead {
@@ -34,14 +38,50 @@ pub trait OwnedAsyncWriter {
         offset: u64,
         ctx: &RequestContext,
     ) -> impl std::future::Future<Output = (FullSlice<Buf>, std::io::Result<()>)> + Send;
+    fn set_len(
+        &self,
+        len: u64,
+        ctx: &RequestContext,
+    ) -> impl Future<Output = std::io::Result<()>> + Send;
 }
 
 /// A wrapper aorund an [`OwnedAsyncWriter`] that uses a [`Buffer`] to batch
 /// small writes into larger writes of size [`Buffer::cap`].
+///
+/// The buffer is flushed if and only if it is full ([`Buffer::pending`] == [`Buffer::cap`]).
+/// This guarantees that writes to the filesystem happen
+/// - at offsets that are multiples of [`Buffer::cap`]
+/// - in lengths that are multiples of [`Buffer::cap`]
+///
+/// Above property is useful for Direct IO, where whatever the
+/// effectively dominating disk-sector/filesystem-block/memory-page size
+/// determines the requirements on
+/// - the alignment of the pointer passed to the read/write operation
+/// - the value of `count` (i.e., the length of the read/write operation)
+///   which must be a multiple of the dominating sector/block/page size.
+///
+/// See [`BufferedWriter::shutdown`] / [`BufferedWriterShutdownMode`] for different
+/// ways of dealing with the special case that the buffer is not full by the time
+/// we are done writing.
+///
+/// The first flush to the underlying `W` happens at offset `start_offset` (arg of [`BufferedWriter::new`]).
+/// The next flush is to offset `start_offset + Buffer::cap`. The one after at `start_offset + 2 * Buffer::cap` and so on.
+///
+/// TODO: decouple buffer capacity from alignment requirement.
+/// Right now we assume [`Buffer::cap`] is the alignment requirement,
+/// but actually [`Buffer::cap`] should only determine how often we flush
+/// while writing, while a separate alignment requirement argument should
+/// be passed to determine alignment requirement. This could be used by
+/// [`BufferedWriterShutdownMode::PadThenTruncate`] to avoid excessive
+/// padding of zeroes. For example, today, with a capacity of 64KiB, we
+/// would pad up to 64KiB-1 bytes of zeroes, then truncate off 64KiB-1.
+/// This is wasteful, e.g., if the alignment requirement is 4KiB, we only
+/// need to pad & truncate up to 4KiB-1 bytes of zeroes
+///
 // TODO(yuchen): For large write, implementing buffer bypass for aligned parts of the write could be beneficial to throughput,
 // since we would avoid copying majority of the data into the internal buffer.
+// https://github.com/neondatabase/neon/issues/10101
 pub struct BufferedWriter<B: Buffer, W> {
-    writer: Arc<W>,
     /// Clone of the buffer that was last submitted to the flush loop.
     /// `None` if no flush request has been submitted, Some forever after.
     pub(super) maybe_flushed: Option<FullSlice<B::IoBuf>>,
@@ -62,9 +102,24 @@ pub struct BufferedWriter<B: Buffer, W> {
     bytes_submitted: u64,
 }
 
+/// How [`BufferedWriter::shutdown`] should deal with pending (=not-yet-flushed) data.
+///
+/// Cf the [`BufferedWriter`] comment's paragraph for context on why we need to think about this.
+pub enum BufferedWriterShutdownMode {
+    /// Drop pending data, don't write back to file.
+    DropTail,
+    /// Pad the pending data with zeroes (cf [`usize::next_multiple_of`]).
+    ZeroPadToNextMultiple(usize),
+    /// Fill the IO buffer with zeroes, flush to disk, the `ftruncate` the
+    /// file to the exact number of bytes written to [`Self`].
+    ///
+    /// TODO: see in [`BufferedWriter`] comment about decoupling buffer capacity from alignment requirement.
+    PadThenTruncate,
+}
+
 impl<B, Buf, W> BufferedWriter<B, W>
 where
-    B: Buffer<IoBuf = Buf> + Send + 'static,
+    B: IoBufAlignedMut + Buffer<IoBuf = Buf> + Send + 'static,
     Buf: IoBufAligned + Send + Sync + CheapCloneForRead,
     W: OwnedAsyncWriter + Send + Sync + 'static + std::fmt::Debug,
 {
@@ -72,7 +127,8 @@ where
     ///
     /// The `buf_new` function provides a way to initialize the owned buffers used by this writer.
     pub fn new(
-        writer: Arc<W>,
+        writer: W,
+        start_offset: u64,
         buf_new: impl Fn() -> B,
         gate_guard: utils::sync::gate::GateGuard,
         cancel: CancellationToken,
@@ -80,7 +136,6 @@ where
         flush_task_span: tracing::Span,
     ) -> Self {
         Self {
-            writer: writer.clone(),
             mutable: Some(buf_new()),
             maybe_flushed: None,
             flush_handle: FlushHandle::spawn_new(
@@ -91,14 +146,10 @@ where
                 ctx.attached_child(),
                 flush_task_span,
             ),
-            bytes_submitted: 0,
+            bytes_submitted: start_offset,
         }
     }
 
-    pub fn as_inner(&self) -> &W {
-        &self.writer
-    }
-
     /// Returns the number of bytes submitted to the background flush task.
     pub fn bytes_submitted(&self) -> u64 {
         self.bytes_submitted
@@ -116,22 +167,80 @@ where
     }
 
     #[cfg_attr(target_os = "macos", allow(dead_code))]
-    pub async fn flush_and_into_inner(
+    pub async fn shutdown(
         mut self,
+        mode: BufferedWriterShutdownMode,
         ctx: &RequestContext,
-    ) -> Result<(u64, Arc<W>), FlushTaskError> {
-        self.flush(ctx).await?;
+    ) -> Result<(u64, W), FlushTaskError> {
+        let mut mutable = self.mutable.take().expect("must not use after an error");
+        let unpadded_pending = mutable.pending();
+        let final_len: u64;
+        let shutdown_req;
+        match mode {
+            BufferedWriterShutdownMode::DropTail => {
+                trace!(pending=%mutable.pending(), "dropping pending data");
+                drop(mutable);
 
+                final_len = self.bytes_submitted;
+                shutdown_req = ShutdownRequest { set_len: None };
+            }
+            BufferedWriterShutdownMode::ZeroPadToNextMultiple(next_multiple) => {
+                let len = mutable.pending();
+                let cap = mutable.cap();
+                assert!(
+                    len <= cap,
+                    "buffer impl ensures this, but let's check because the extend_with below would panic if we go beyond"
+                );
+                let padded_len = len.next_multiple_of(next_multiple);
+                assert!(
+                    padded_len <= cap,
+                    "caller specified a multiple that is larger than the buffer capacity"
+                );
+                let count = padded_len - len;
+                mutable.extend_with(0, count);
+                trace!(count, "padding with zeros");
+                self.mutable = Some(mutable);
+
+                final_len = self.bytes_submitted + padded_len.into_u64();
+                shutdown_req = ShutdownRequest { set_len: None };
+            }
+            BufferedWriterShutdownMode::PadThenTruncate => {
+                let len = mutable.pending();
+                let cap = mutable.cap();
+                // TODO: see struct comment TODO on decoupling buffer capacity from alignment requirement.
+                let alignment_requirement = cap;
+                assert!(len <= cap, "buffer impl should ensure this");
+                let padding_end_offset = len.next_multiple_of(alignment_requirement);
+                assert!(
+                    padding_end_offset <= cap,
+                    "{padding_end_offset} <= {cap}  ({alignment_requirement})"
+                );
+                let count = padding_end_offset - len;
+                mutable.extend_with(0, count);
+                trace!(count, "padding with zeros");
+                self.mutable = Some(mutable);
+
+                final_len = self.bytes_submitted + len.into_u64();
+                shutdown_req = ShutdownRequest {
+                    // Avoid set_len call if we didn't need to pad anything.
+                    set_len: if count > 0 { Some(final_len) } else { None },
+                };
+            }
+        };
+        let padded_pending = self.mutable.as_ref().map(|b| b.pending());
+        trace!(unpadded_pending, padded_pending, "padding done");
+        if self.mutable.is_some() {
+            self.flush(ctx).await?;
+        }
         let Self {
-            mutable: buf,
+            mutable: _,
             maybe_flushed: _,
-            writer,
             mut flush_handle,
-            bytes_submitted: bytes_amount,
+            bytes_submitted: _,
         } = self;
-        flush_handle.shutdown().await?;
-        assert!(buf.is_some());
-        Ok((bytes_amount, writer))
+        let writer = flush_handle.shutdown(shutdown_req).await?;
+
+        Ok((final_len, writer))
     }
 
     #[cfg(test)]
@@ -235,6 +344,10 @@ pub trait Buffer {
     /// panics if `other.len() > self.cap() - self.pending()`.
     fn extend_from_slice(&mut self, other: &[u8]);
 
+    /// Add `count` bytes `val` into `self`.
+    /// Panics if `count > self.cap() - self.pending()`.
+    fn extend_with(&mut self, val: u8, count: usize);
+
     /// Number of bytes in the buffer.
     fn pending(&self) -> usize;
 
@@ -262,6 +375,14 @@ impl Buffer for IoBufferMut {
         IoBufferMut::extend_from_slice(self, other);
     }
 
+    fn extend_with(&mut self, val: u8, count: usize) {
+        if self.len() + count > self.cap() {
+            panic!("Buffer capacity exceeded");
+        }
+
+        IoBufferMut::put_bytes(self, val, count);
+    }
+
     fn pending(&self) -> usize {
         self.len()
     }
@@ -284,26 +405,22 @@ impl Buffer for IoBufferMut {
 mod tests {
     use std::sync::Mutex;
 
+    use rstest::rstest;
+
     use super::*;
     use crate::context::{DownloadBehavior, RequestContext};
     use crate::task_mgr::TaskKind;
 
+    #[derive(Debug, PartialEq, Eq)]
+    enum Op {
+        Write { buf: Vec<u8>, offset: u64 },
+        SetLen { len: u64 },
+    }
+
     #[derive(Default, Debug)]
     struct RecorderWriter {
         /// record bytes and write offsets.
-        writes: Mutex<Vec<(Vec<u8>, u64)>>,
-    }
-
-    impl RecorderWriter {
-        /// Gets recorded bytes and write offsets.
-        fn get_writes(&self) -> Vec<Vec<u8>> {
-            self.writes
-                .lock()
-                .unwrap()
-                .iter()
-                .map(|(buf, _)| buf.clone())
-                .collect()
-        }
+        recording: Mutex<Vec<Op>>,
     }
 
     impl OwnedAsyncWriter for RecorderWriter {
@@ -313,28 +430,42 @@ mod tests {
             offset: u64,
             _: &RequestContext,
         ) -> (FullSlice<Buf>, std::io::Result<()>) {
-            self.writes
-                .lock()
-                .unwrap()
-                .push((Vec::from(&buf[..]), offset));
+            self.recording.lock().unwrap().push(Op::Write {
+                buf: Vec::from(&buf[..]),
+                offset,
+            });
             (buf, Ok(()))
         }
+        async fn set_len(&self, len: u64, _ctx: &RequestContext) -> std::io::Result<()> {
+            self.recording.lock().unwrap().push(Op::SetLen { len });
+            Ok(())
+        }
     }
 
     fn test_ctx() -> RequestContext {
         RequestContext::new(TaskKind::UnitTest, DownloadBehavior::Error)
     }
 
+    #[rstest]
     #[tokio::test]
-    async fn test_write_all_borrowed_always_goes_through_buffer() -> anyhow::Result<()> {
+    async fn test_write_all_borrowed_always_goes_through_buffer(
+        #[values(
+            BufferedWriterShutdownMode::DropTail,
+            BufferedWriterShutdownMode::ZeroPadToNextMultiple(2),
+            BufferedWriterShutdownMode::PadThenTruncate
+        )]
+        mode: BufferedWriterShutdownMode,
+    ) -> anyhow::Result<()> {
         let ctx = test_ctx();
         let ctx = &ctx;
-        let recorder = Arc::new(RecorderWriter::default());
+        let recorder = RecorderWriter::default();
         let gate = utils::sync::gate::Gate::default();
         let cancel = CancellationToken::new();
+        let cap = 4;
         let mut writer = BufferedWriter::<_, RecorderWriter>::new(
             recorder,
-            || IoBufferMut::with_capacity(2),
+            0,
+            || IoBufferMut::with_capacity(cap),
             gate.enter()?,
             cancel,
             ctx,
@@ -344,23 +475,89 @@ mod tests {
         writer.write_buffered_borrowed(b"abc", ctx).await?;
         writer.write_buffered_borrowed(b"", ctx).await?;
         writer.write_buffered_borrowed(b"d", ctx).await?;
-        writer.write_buffered_borrowed(b"e", ctx).await?;
-        writer.write_buffered_borrowed(b"fg", ctx).await?;
-        writer.write_buffered_borrowed(b"hi", ctx).await?;
-        writer.write_buffered_borrowed(b"j", ctx).await?;
-        writer.write_buffered_borrowed(b"klmno", ctx).await?;
+        writer.write_buffered_borrowed(b"efg", ctx).await?;
+        writer.write_buffered_borrowed(b"hijklm", ctx).await?;
 
-        let (_, recorder) = writer.flush_and_into_inner(ctx).await?;
-        assert_eq!(
-            recorder.get_writes(),
-            {
-                let expect: &[&[u8]] = &[b"ab", b"cd", b"ef", b"gh", b"ij", b"kl", b"mn", b"o"];
-                expect
+        let mut expect = {
+            [(0, b"abcd"), (4, b"efgh"), (8, b"ijkl")]
+                .into_iter()
+                .map(|(offset, v)| Op::Write {
+                    offset,
+                    buf: v[..].to_vec(),
+                })
+                .collect::<Vec<_>>()
+        };
+        let expect_next_offset = 12;
+
+        match &mode {
+            BufferedWriterShutdownMode::DropTail => (),
+            // We test the case with padding to next multiple of 2 so that it's different
+            // from the alignment requirement of 4 inferred from buffer capacity.
+            // See TODOs in the `BufferedWriter` struct comment on decoupling buffer capacity from alignment requirement.
+            BufferedWriterShutdownMode::ZeroPadToNextMultiple(2) => {
+                expect.push(Op::Write {
+                    offset: expect_next_offset,
+                    // it's legitimate for pad-to-next multiple 2 to be < alignment requirement 4 inferred from buffer capacity
+                    buf: b"m\0".to_vec(),
+                });
             }
-            .iter()
-            .map(|v| v[..].to_vec())
-            .collect::<Vec<_>>()
+            BufferedWriterShutdownMode::ZeroPadToNextMultiple(_) => unimplemented!(),
+            BufferedWriterShutdownMode::PadThenTruncate => {
+                expect.push(Op::Write {
+                    offset: expect_next_offset,
+                    buf: b"m\0\0\0".to_vec(),
+                });
+                expect.push(Op::SetLen { len: 13 });
+            }
+        }
+
+        let (_, recorder) = writer.shutdown(mode, ctx).await?;
+        assert_eq!(&*recorder.recording.lock().unwrap(), &expect);
+        Ok(())
+    }
+
+    #[tokio::test]
+    async fn test_set_len_is_skipped_if_not_needed() -> anyhow::Result<()> {
+        let ctx = test_ctx();
+        let ctx = &ctx;
+        let recorder = RecorderWriter::default();
+        let gate = utils::sync::gate::Gate::default();
+        let cancel = CancellationToken::new();
+        let cap = 4;
+        let mut writer = BufferedWriter::<_, RecorderWriter>::new(
+            recorder,
+            0,
+            || IoBufferMut::with_capacity(cap),
+            gate.enter()?,
+            cancel,
+            ctx,
+            tracing::Span::none(),
         );
+
+        // write a multiple of `cap`
+        writer.write_buffered_borrowed(b"abc", ctx).await?;
+        writer.write_buffered_borrowed(b"defgh", ctx).await?;
+
+        let (_, recorder) = writer
+            .shutdown(BufferedWriterShutdownMode::PadThenTruncate, ctx)
+            .await?;
+
+        let expect = {
+            [(0, b"abcd"), (4, b"efgh")]
+                .into_iter()
+                .map(|(offset, v)| Op::Write {
+                    offset,
+                    buf: v[..].to_vec(),
+                })
+                .collect::<Vec<_>>()
+        };
+
+        assert_eq!(
+            &*recorder.recording.lock().unwrap(),
+            &expect,
+            "set_len should not be called if the buffer is already aligned"
+        );
+
         Ok(())
     }
 }
diff --git a/pageserver/src/virtual_file/owned_buffers_io/write/flush.rs b/pageserver/src/virtual_file/owned_buffers_io/write/flush.rs
index c076ba0eca..b41a9f6cd2 100644
--- a/pageserver/src/virtual_file/owned_buffers_io/write/flush.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/write/flush.rs
@@ -1,8 +1,7 @@
 use std::ops::ControlFlow;
-use std::sync::Arc;
 
 use tokio_util::sync::CancellationToken;
-use tracing::{Instrument, info, info_span, warn};
+use tracing::{Instrument, info_span, warn};
 use utils::sync::duplex;
 
 use super::{Buffer, CheapCloneForRead, OwnedAsyncWriter};
@@ -19,18 +18,36 @@ pub struct FlushHandle<Buf, W> {
 pub struct FlushHandleInner<Buf, W> {
     /// A bi-directional channel that sends (buffer, offset) for writes,
     /// and receives recyled buffer.
-    channel: duplex::mpsc::Duplex<FlushRequest<Buf>, FullSlice<Buf>>,
+    channel: duplex::mpsc::Duplex<Request<Buf>, FullSlice<Buf>>,
     /// Join handle for the background flush task.
-    join_handle: tokio::task::JoinHandle<Result<Arc<W>, FlushTaskError>>,
+    join_handle: tokio::task::JoinHandle<Result<W, FlushTaskError>>,
 }
 
 struct FlushRequest<Buf> {
     slice: FullSlice<Buf>,
     offset: u64,
     #[cfg(test)]
-    ready_to_flush_rx: tokio::sync::oneshot::Receiver<()>,
+    ready_to_flush_rx: Option<tokio::sync::oneshot::Receiver<()>>,
     #[cfg(test)]
-    done_flush_tx: tokio::sync::oneshot::Sender<()>,
+    done_flush_tx: Option<tokio::sync::oneshot::Sender<()>>,
+}
+
+pub struct ShutdownRequest {
+    pub set_len: Option<u64>,
+}
+
+enum Request<Buf> {
+    Flush(FlushRequest<Buf>),
+    Shutdown(ShutdownRequest),
+}
+
+impl<Buf> Request<Buf> {
+    fn op_str(&self) -> &'static str {
+        match self {
+            Request::Flush(_) => "flush",
+            Request::Shutdown(_) => "shutdown",
+        }
+    }
 }
 
 /// Constructs a request and a control object for a new flush operation.
@@ -52,8 +69,8 @@ fn new_flush_op<Buf>(slice: FullSlice<Buf>, offset: u64) -> (FlushRequest<Buf>,
     let request = FlushRequest {
         slice,
         offset,
-        ready_to_flush_rx,
-        done_flush_tx,
+        ready_to_flush_rx: Some(ready_to_flush_rx),
+        done_flush_tx: Some(done_flush_tx),
     };
     (request, control)
 }
@@ -120,7 +137,7 @@ where
     /// The queue depth is 1, and the passed-in `buf` seeds the queue depth.
     /// I.e., the passed-in buf is immediately available to the handle as a recycled buffer.
     pub fn spawn_new<B>(
-        file: Arc<W>,
+        file: W,
         buf: B,
         gate_guard: utils::sync::gate::GateGuard,
         cancel: CancellationToken,
@@ -160,10 +177,7 @@ where
         let (request, flush_control) = new_flush_op(slice, offset);
 
         // Submits the buffer to the background task.
-        let submit = self.inner_mut().channel.send(request).await;
-        if submit.is_err() {
-            return self.handle_error().await;
-        }
+        self.send(Request::Flush(request)).await?;
 
         // Wait for an available buffer from the background flush task.
         // This is the BACKPRESSURE mechanism: if the flush task can't keep up,
@@ -175,15 +189,28 @@ where
         Ok((recycled, flush_control))
     }
 
+    /// Sends poison pill to flush task and waits for it to exit.
+    pub async fn shutdown(&mut self, req: ShutdownRequest) -> Result<W, FlushTaskError> {
+        self.send(Request::Shutdown(req)).await?;
+        self.wait().await
+    }
+
+    async fn send(&mut self, request: Request<Buf>) -> Result<(), FlushTaskError> {
+        let submit = self.inner_mut().channel.send(request).await;
+        if submit.is_err() {
+            return self.handle_error().await;
+        }
+        Ok(())
+    }
+
     async fn handle_error<T>(&mut self) -> Result<T, FlushTaskError> {
         Err(self
-            .shutdown()
+            .wait()
             .await
             .expect_err("flush task only disconnects duplex if it exits with an error"))
     }
 
-    /// Cleans up the channel, join the flush task.
-    pub async fn shutdown(&mut self) -> Result<Arc<W>, FlushTaskError> {
+    async fn wait(&mut self) -> Result<W, FlushTaskError> {
         let handle = self
             .inner
             .take()
@@ -205,9 +232,9 @@ where
 pub struct FlushBackgroundTask<Buf, W> {
     /// A bi-directional channel that receives (buffer, offset) for writes,
     /// and send back recycled buffer.
-    channel: duplex::mpsc::Duplex<FullSlice<Buf>, FlushRequest<Buf>>,
+    channel: duplex::mpsc::Duplex<FullSlice<Buf>, Request<Buf>>,
     /// A writter for persisting data to disk.
-    writer: Arc<W>,
+    writer: W,
     ctx: RequestContext,
     cancel: CancellationToken,
     /// Prevent timeline from shuting down until the flush background task finishes flushing all remaining buffers to disk.
@@ -227,8 +254,8 @@ where
 {
     /// Creates a new background flush task.
     fn new(
-        channel: duplex::mpsc::Duplex<FullSlice<Buf>, FlushRequest<Buf>>,
-        file: Arc<W>,
+        channel: duplex::mpsc::Duplex<FullSlice<Buf>, Request<Buf>>,
+        file: W,
         gate_guard: utils::sync::gate::GateGuard,
         cancel: CancellationToken,
         ctx: RequestContext,
@@ -243,18 +270,12 @@ where
     }
 
     /// Runs the background flush task.
-    async fn run(mut self) -> Result<Arc<W>, FlushTaskError> {
+    async fn run(mut self) -> Result<W, FlushTaskError> {
         //  Exit condition: channel is closed and there is no remaining buffer to be flushed
         while let Some(request) = self.channel.recv().await {
-            #[cfg(test)]
-            {
-                // In test, wait for control to signal that we are ready to flush.
-                if request.ready_to_flush_rx.await.is_err() {
-                    tracing::debug!("control dropped");
-                }
-            }
+            let op_kind = request.op_str();
 
-            // Write slice to disk at `offset`.
+            // Perform the requested operation.
             //
             // Error handling happens according to the current policy of crashing
             // on fatal IO errors and retrying in place otherwise (deeming all other errors retryable).
@@ -263,52 +284,112 @@ where
             //
             // TODO: use utils::backoff::retry once async closures are actually usable
             //
-            let mut slice_storage = Some(request.slice);
+            let mut request_storage = Some(request);
             for attempt in 1.. {
                 if self.cancel.is_cancelled() {
                     return Err(FlushTaskError::Cancelled);
                 }
                 let result = async {
-                    if attempt > 1 {
-                        info!("retrying flush");
-                    }
-                    let slice = slice_storage.take().expect(
+                    let request: Request<Buf> = request_storage .take().expect(
                         "likely previous invocation of this future didn't get polled to completion",
                     );
-                    // Don't cancel this write by doing tokio::select with self.cancel.cancelled().
+                    match &request {
+                        Request::Shutdown(ShutdownRequest { set_len: None }) => {
+                            request_storage = Some(request);
+                            return ControlFlow::Break(());
+                        },
+                        Request::Flush(_) | Request::Shutdown(ShutdownRequest { set_len: Some(_) }) => {
+                        },
+                    }
+                    if attempt > 1 {
+                        warn!(op=%request.op_str(), "retrying");
+                    }
+                    // borrows so we can async move the requests into async block while not moving these borrows here
+                    let writer = &self.writer;
+                    let request_storage = &mut request_storage;
+                    let ctx = &self.ctx;
+                    let io_fut = match request {
+                        Request::Flush(FlushRequest { slice, offset, #[cfg(test)] ready_to_flush_rx, #[cfg(test)] done_flush_tx }) => futures::future::Either::Left(async move {
+                            #[cfg(test)]
+                            if let Some(ready_to_flush_rx) = ready_to_flush_rx {
+                                {
+                                    // In test, wait for control to signal that we are ready to flush.
+                                    if ready_to_flush_rx.await.is_err() {
+                                        tracing::debug!("control dropped");
+                                    }
+                                }
+                            }
+                            let (slice, res) = writer.write_all_at(slice, offset, ctx).await;
+                            *request_storage = Some(Request::Flush(FlushRequest {
+                                slice,
+                                offset,
+                                #[cfg(test)]
+                                ready_to_flush_rx: None, // the contract is that we notify before first attempt
+                                #[cfg(test)]
+                                done_flush_tx
+                            }));
+                            res
+                        }),
+                        Request::Shutdown(ShutdownRequest { set_len }) => futures::future::Either::Right(async move {
+                            let set_len = set_len.expect("we filter out the None case above");
+                            let res = writer.set_len(set_len, ctx).await;
+                            *request_storage = Some(Request::Shutdown(ShutdownRequest {
+                                set_len: Some(set_len),
+                            }));
+                            res
+                        }),
+                    };
+                    // Don't cancel the io_fut by doing tokio::select with self.cancel.cancelled().
                     // The underlying tokio-epoll-uring slot / kernel operation is still ongoing and occupies resources.
                     // If we retry indefinitely, we'll deplete those resources.
                     // Future: teach tokio-epoll-uring io_uring operation cancellation, but still,
                     // wait for cancelled ops to complete and discard their error.
-                    let (slice, res) = self.writer.write_all_at(slice, request.offset, &self.ctx).await;
-                    slice_storage = Some(slice);
+                    let res = io_fut.await;
                     let res = res.maybe_fatal_err("owned_buffers_io flush");
                     let Err(err) = res else {
+                        if attempt > 1 {
+                            warn!(op=%op_kind, "retry succeeded");
+                        }
                         return ControlFlow::Break(());
                     };
                     warn!(%err, "error flushing buffered writer buffer to disk, retrying after backoff");
                     utils::backoff::exponential_backoff(attempt, 1.0, 10.0, &self.cancel).await;
                     ControlFlow::Continue(())
                 }
-                .instrument(info_span!("flush_attempt", %attempt))
+                .instrument(info_span!("attempt", %attempt, %op_kind))
                 .await;
                 match result {
                     ControlFlow::Break(()) => break,
                     ControlFlow::Continue(()) => continue,
                 }
             }
-            let slice = slice_storage.expect("loop must have run at least once");
+            let request = request_storage.expect("loop must have run at least once");
 
-            #[cfg(test)]
-            {
-                // In test, tell control we are done flushing buffer.
-                if request.done_flush_tx.send(()).is_err() {
-                    tracing::debug!("control dropped");
+            let slice = match request {
+                Request::Flush(FlushRequest {
+                    slice,
+                    #[cfg(test)]
+                    mut done_flush_tx,
+                    ..
+                }) => {
+                    #[cfg(test)]
+                    {
+                        // In test, tell control we are done flushing buffer.
+                        if done_flush_tx.take().expect("always Some").send(()).is_err() {
+                            tracing::debug!("control dropped");
+                        }
+                    }
+                    slice
                 }
-            }
+                Request::Shutdown(_) => {
+                    // next iteration will observe recv() returning None
+                    continue;
+                }
+            };
 
             // Sends the buffer back to the handle for reuse. The handle is in charged of cleaning the buffer.
-            if self.channel.send(slice).await.is_err() {
+            let send_res = self.channel.send(slice).await;
+            if send_res.is_err() {
                 // Although channel is closed. Still need to finish flushing the remaining buffers.
                 continue;
             }
diff --git a/pageserver/src/virtual_file/temporary.rs b/pageserver/src/virtual_file/temporary.rs
new file mode 100644
index 0000000000..84f69f9f7f
--- /dev/null
+++ b/pageserver/src/virtual_file/temporary.rs
@@ -0,0 +1,110 @@
+use tracing::error;
+use utils::sync::gate::GateGuard;
+
+use crate::context::RequestContext;
+
+use super::{
+    MaybeFatalIo, VirtualFile,
+    owned_buffers_io::{
+        io_buf_aligned::IoBufAligned, io_buf_ext::FullSlice, write::OwnedAsyncWriter,
+    },
+};
+
+/// A wrapper around [`super::VirtualFile`] that deletes the file on drop.
+/// For use as a [`OwnedAsyncWriter`] in [`super::owned_buffers_io::write::BufferedWriter`].
+#[derive(Debug)]
+pub struct TempVirtualFile {
+    inner: Option<Inner>,
+}
+
+#[derive(Debug)]
+struct Inner {
+    file: VirtualFile,
+    /// Gate guard is held on as long as we need to do operations in the path (delete on drop)
+    _gate_guard: GateGuard,
+}
+
+impl OwnedAsyncWriter for TempVirtualFile {
+    fn write_all_at<Buf: IoBufAligned + Send>(
+        &self,
+        buf: FullSlice<Buf>,
+        offset: u64,
+        ctx: &RequestContext,
+    ) -> impl std::future::Future<Output = (FullSlice<Buf>, std::io::Result<()>)> + Send {
+        VirtualFile::write_all_at(self, buf, offset, ctx)
+    }
+
+    async fn set_len(&self, len: u64, ctx: &RequestContext) -> std::io::Result<()> {
+        VirtualFile::set_len(self, len, ctx).await
+    }
+}
+
+impl Drop for TempVirtualFile {
+    fn drop(&mut self) {
+        let Some(Inner { file, _gate_guard }) = self.inner.take() else {
+            return;
+        };
+        let path = file.path();
+        if let Err(e) =
+            std::fs::remove_file(path).maybe_fatal_err("failed to remove the virtual file")
+        {
+            error!(err=%e, path=%path, "failed to remove");
+        }
+        drop(_gate_guard);
+    }
+}
+
+impl std::ops::Deref for TempVirtualFile {
+    type Target = VirtualFile;
+
+    fn deref(&self) -> &Self::Target {
+        &self
+            .inner
+            .as_ref()
+            .expect("only None after into_inner or drop")
+            .file
+    }
+}
+
+impl std::ops::DerefMut for TempVirtualFile {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self
+            .inner
+            .as_mut()
+            .expect("only None after into_inner or drop")
+            .file
+    }
+}
+
+impl TempVirtualFile {
+    /// The caller is responsible for ensuring that the path of `virtual_file` is not reused
+    /// until after this TempVirtualFile's `Drop` impl has completed.
+    /// Failure to do so will result in unlinking of the reused path by the original instance's Drop impl.
+    /// The best way to do so is by using a monotonic counter as a disambiguator.
+    /// TODO: centralize this disambiguator pattern inside this struct.
+    ///   => <https://github.com/neondatabase/neon/pull/11549#issuecomment-2824592831>
+    pub fn new(virtual_file: VirtualFile, gate_guard: GateGuard) -> Self {
+        Self {
+            inner: Some(Inner {
+                file: virtual_file,
+                _gate_guard: gate_guard,
+            }),
+        }
+    }
+
+    /// Dismantle this wrapper and return the underlying [`VirtualFile`].
+    /// This disables auto-unlinking functionality that is the essence of this wrapper.
+    ///
+    /// The gate guard is dropped as well; it is the callers responsibility to ensure filesystem
+    /// operations after calls to this functions are still gated by some other gate guard.
+    ///
+    /// TODO:
+    /// - centralize the common usage pattern of callers (sync_all(self), rename(self, dst), sync_all(dst.parent))
+    ///   => <https://github.com/neondatabase/neon/pull/11549#issuecomment-2824592831>
+    pub fn disarm_into_inner(mut self) -> VirtualFile {
+        self.inner
+            .take()
+            .expect("only None after into_inner or drop, and we are into_inner, and we consume")
+            .file
+    }
+}
diff --git a/poetry.lock b/poetry.lock
index 08732fd641..1a772d3415 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1274,14 +1274,14 @@ files = [
 
 [[package]]
 name = "h11"
-version = "0.14.0"
+version = "0.16.0"
 description = "A pure-Python, bring-your-own-I/O implementation of HTTP/1.1"
 optional = false
-python-versions = ">=3.7"
+python-versions = ">=3.8"
 groups = ["main"]
 files = [
-    {file = "h11-0.14.0-py3-none-any.whl", hash = "sha256:e3fe4ac4b851c468cc8363d500db52c2ead036020723024a109d37346efaa761"},
-    {file = "h11-0.14.0.tar.gz", hash = "sha256:8f19fbbe99e72420ff35c00b27a34cb9937e902a8b810e2c88300c6f0a3b699d"},
+    {file = "h11-0.16.0-py3-none-any.whl", hash = "sha256:63cf8bbe7522de3bf65932fda1d9c2772064ffb3dae62d55932da54b31cb6c86"},
+    {file = "h11-0.16.0.tar.gz", hash = "sha256:4e35b956cf45792e4caa5885e69fba00bdbc6ffafbfa020300e549b208ee5ff1"},
 ]
 
 [[package]]
@@ -1314,25 +1314,25 @@ files = [
 
 [[package]]
 name = "httpcore"
-version = "1.0.3"
+version = "1.0.9"
 description = "A minimal low-level HTTP client."
 optional = false
 python-versions = ">=3.8"
 groups = ["main"]
 files = [
-    {file = "httpcore-1.0.3-py3-none-any.whl", hash = "sha256:9a6a501c3099307d9fd76ac244e08503427679b1e81ceb1d922485e2f2462ad2"},
-    {file = "httpcore-1.0.3.tar.gz", hash = "sha256:5c0f9546ad17dac4d0772b0808856eb616eb8b48ce94f49ed819fd6982a8a544"},
+    {file = "httpcore-1.0.9-py3-none-any.whl", hash = "sha256:2d400746a40668fc9dec9810239072b40b4484b640a8c38fd654a024c7a1bf55"},
+    {file = "httpcore-1.0.9.tar.gz", hash = "sha256:6e34463af53fd2ab5d807f399a9b45ea31c3dfa2276f15a2c3f00afff6e176e8"},
 ]
 
 [package.dependencies]
 certifi = "*"
-h11 = ">=0.13,<0.15"
+h11 = ">=0.16"
 
 [package.extras]
 asyncio = ["anyio (>=4.0,<5.0)"]
 http2 = ["h2 (>=3,<5)"]
 socks = ["socksio (==1.*)"]
-trio = ["trio (>=0.22.0,<0.24.0)"]
+trio = ["trio (>=0.22.0,<1.0)"]
 
 [[package]]
 name = "httpx"
diff --git a/proxy/src/lib.rs b/proxy/src/lib.rs
index a9e5fbc85b..d1f8430b8a 100644
--- a/proxy/src/lib.rs
+++ b/proxy/src/lib.rs
@@ -91,6 +91,7 @@ mod jemalloc;
 mod logging;
 mod metrics;
 mod parse;
+mod pglb;
 mod protocol2;
 mod proxy;
 mod rate_limiter;
diff --git a/proxy/src/pglb/inprocess.rs b/proxy/src/pglb/inprocess.rs
new file mode 100644
index 0000000000..905f82f909
--- /dev/null
+++ b/proxy/src/pglb/inprocess.rs
@@ -0,0 +1,193 @@
+#![allow(dead_code, reason = "TODO: work in progress")]
+
+use std::pin::{Pin, pin};
+use std::sync::Arc;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::task::{Context, Poll};
+use std::{fmt, io};
+
+use tokio::io::{AsyncRead, AsyncWrite, DuplexStream, ReadBuf};
+use tokio::sync::mpsc;
+
+const STREAM_CHANNEL_SIZE: usize = 16;
+const MAX_STREAM_BUFFER_SIZE: usize = 4096;
+
+#[derive(Debug)]
+pub struct Connection {
+    stream_sender: mpsc::Sender<Stream>,
+    stream_receiver: mpsc::Receiver<Stream>,
+    stream_id_counter: Arc<AtomicUsize>,
+}
+
+impl Connection {
+    pub fn new() -> (Connection, Connection) {
+        let (sender_a, receiver_a) = mpsc::channel(STREAM_CHANNEL_SIZE);
+        let (sender_b, receiver_b) = mpsc::channel(STREAM_CHANNEL_SIZE);
+
+        let stream_id_counter = Arc::new(AtomicUsize::new(1));
+
+        let conn_a = Connection {
+            stream_sender: sender_a,
+            stream_receiver: receiver_b,
+            stream_id_counter: Arc::clone(&stream_id_counter),
+        };
+        let conn_b = Connection {
+            stream_sender: sender_b,
+            stream_receiver: receiver_a,
+            stream_id_counter,
+        };
+
+        (conn_a, conn_b)
+    }
+
+    #[inline]
+    fn next_stream_id(&self) -> StreamId {
+        StreamId(self.stream_id_counter.fetch_add(1, Ordering::Relaxed))
+    }
+
+    #[tracing::instrument(skip_all, fields(stream_id = tracing::field::Empty, err))]
+    pub async fn open_stream(&self) -> io::Result<Stream> {
+        let (local, remote) = tokio::io::duplex(MAX_STREAM_BUFFER_SIZE);
+        let stream_id = self.next_stream_id();
+        tracing::Span::current().record("stream_id", stream_id.0);
+
+        let local = Stream {
+            inner: local,
+            id: stream_id,
+        };
+        let remote = Stream {
+            inner: remote,
+            id: stream_id,
+        };
+
+        self.stream_sender
+            .send(remote)
+            .await
+            .map_err(io::Error::other)?;
+
+        Ok(local)
+    }
+
+    #[tracing::instrument(skip_all, fields(stream_id = tracing::field::Empty, err))]
+    pub async fn accept_stream(&mut self) -> io::Result<Option<Stream>> {
+        Ok(self.stream_receiver.recv().await.inspect(|stream| {
+            tracing::Span::current().record("stream_id", stream.id.0);
+        }))
+    }
+}
+
+#[derive(Copy, Clone, Debug)]
+pub struct StreamId(usize);
+
+impl fmt::Display for StreamId {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+// TODO: Proper closing. Currently Streams can outlive their Connections.
+// Carry WeakSender and check strong_count?
+#[derive(Debug)]
+pub struct Stream {
+    inner: DuplexStream,
+    id: StreamId,
+}
+
+impl Stream {
+    #[inline]
+    pub fn id(&self) -> StreamId {
+        self.id
+    }
+}
+
+impl AsyncRead for Stream {
+    #[tracing::instrument(level = "debug", skip_all, fields(stream_id = %self.id))]
+    #[inline]
+    fn poll_read(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        pin!(&mut self.inner).poll_read(cx, buf)
+    }
+}
+
+impl AsyncWrite for Stream {
+    #[tracing::instrument(level = "debug", skip_all, fields(stream_id = %self.id))]
+    #[inline]
+    fn poll_write(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<Result<usize, io::Error>> {
+        pin!(&mut self.inner).poll_write(cx, buf)
+    }
+
+    #[tracing::instrument(level = "debug", skip_all, fields(stream_id = %self.id))]
+    #[inline]
+    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+        pin!(&mut self.inner).poll_flush(cx)
+    }
+
+    #[tracing::instrument(level = "debug", skip_all, fields(stream_id = %self.id))]
+    #[inline]
+    fn poll_shutdown(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Result<(), io::Error>> {
+        pin!(&mut self.inner).poll_shutdown(cx)
+    }
+
+    #[tracing::instrument(level = "debug", skip_all, fields(stream_id = %self.id))]
+    #[inline]
+    fn poll_write_vectored(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        bufs: &[io::IoSlice<'_>],
+    ) -> Poll<Result<usize, io::Error>> {
+        pin!(&mut self.inner).poll_write_vectored(cx, bufs)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.inner.is_write_vectored()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+    use super::*;
+
+    #[tokio::test]
+    async fn test_simple_roundtrip() {
+        let (client, mut server) = Connection::new();
+
+        let server_task = tokio::spawn(async move {
+            while let Some(mut stream) = server.accept_stream().await.unwrap() {
+                tokio::spawn(async move {
+                    let mut buf = [0; 64];
+                    loop {
+                        match stream.read(&mut buf).await.unwrap() {
+                            0 => break,
+                            n => stream.write(&buf[..n]).await.unwrap(),
+                        };
+                    }
+                });
+            }
+        });
+
+        let mut stream = client.open_stream().await.unwrap();
+        stream.write_all(b"hello!").await.unwrap();
+        let mut buf = [0; 64];
+        let n = stream.read(&mut buf).await.unwrap();
+        assert_eq!(n, 6);
+        assert_eq!(&buf[..n], b"hello!");
+
+        drop(stream);
+        drop(client);
+        server_task.await.unwrap();
+    }
+}
diff --git a/proxy/src/pglb/mod.rs b/proxy/src/pglb/mod.rs
new file mode 100644
index 0000000000..1088859fb9
--- /dev/null
+++ b/proxy/src/pglb/mod.rs
@@ -0,0 +1 @@
+pub mod inprocess;
diff --git a/proxy/src/protocol2.rs b/proxy/src/protocol2.rs
index ecd9882f53..0793998639 100644
--- a/proxy/src/protocol2.rs
+++ b/proxy/src/protocol2.rs
@@ -12,7 +12,7 @@ use pin_project_lite::pin_project;
 use smol_str::SmolStr;
 use strum_macros::FromRepr;
 use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, ReadBuf};
-use zerocopy::{FromBytes, FromZeroes};
+use zerocopy::{FromBytes, Immutable, KnownLayout, Unaligned, network_endian};
 
 pin_project! {
     /// A chained [`AsyncRead`] with [`AsyncWrite`] passthrough
@@ -339,49 +339,49 @@ trait BufExt: Sized {
 }
 impl BufExt for BytesMut {
     fn try_get<T: FromBytes>(&mut self) -> Option<T> {
-        let res = T::read_from_prefix(self)?;
+        let (res, _) = T::read_from_prefix(self).ok()?;
         self.advance(size_of::<T>());
         Some(res)
     }
 }
 
-#[derive(FromBytes, FromZeroes, Copy, Clone)]
-#[repr(C)]
+#[derive(FromBytes, KnownLayout, Immutable, Unaligned, Copy, Clone)]
+#[repr(C, packed)]
 struct ProxyProtocolV2Header {
     signature: [u8; 12],
     version_and_command: u8,
     protocol_and_family: u8,
-    len: zerocopy::byteorder::network_endian::U16,
+    len: network_endian::U16,
 }
 
-#[derive(FromBytes, FromZeroes, Copy, Clone)]
-#[repr(C)]
+#[derive(FromBytes, KnownLayout, Immutable, Unaligned, Copy, Clone)]
+#[repr(C, packed)]
 struct ProxyProtocolV2HeaderV4 {
     src_addr: NetworkEndianIpv4,
     dst_addr: NetworkEndianIpv4,
-    src_port: zerocopy::byteorder::network_endian::U16,
-    dst_port: zerocopy::byteorder::network_endian::U16,
+    src_port: network_endian::U16,
+    dst_port: network_endian::U16,
 }
 
-#[derive(FromBytes, FromZeroes, Copy, Clone)]
-#[repr(C)]
+#[derive(FromBytes, KnownLayout, Immutable, Unaligned, Copy, Clone)]
+#[repr(C, packed)]
 struct ProxyProtocolV2HeaderV6 {
     src_addr: NetworkEndianIpv6,
     dst_addr: NetworkEndianIpv6,
-    src_port: zerocopy::byteorder::network_endian::U16,
-    dst_port: zerocopy::byteorder::network_endian::U16,
+    src_port: network_endian::U16,
+    dst_port: network_endian::U16,
 }
 
-#[derive(FromBytes, FromZeroes, Copy, Clone)]
-#[repr(C)]
+#[derive(FromBytes, KnownLayout, Immutable, Unaligned, Copy, Clone)]
+#[repr(C, packed)]
 struct TlvHeader {
     kind: u8,
-    len: zerocopy::byteorder::network_endian::U16,
+    len: network_endian::U16,
 }
 
-#[derive(FromBytes, FromZeroes, Copy, Clone)]
+#[derive(FromBytes, KnownLayout, Immutable, Unaligned, Copy, Clone)]
 #[repr(transparent)]
-struct NetworkEndianIpv4(zerocopy::byteorder::network_endian::U32);
+struct NetworkEndianIpv4(network_endian::U32);
 impl NetworkEndianIpv4 {
     #[inline]
     fn get(self) -> Ipv4Addr {
@@ -389,9 +389,9 @@ impl NetworkEndianIpv4 {
     }
 }
 
-#[derive(FromBytes, FromZeroes, Copy, Clone)]
+#[derive(FromBytes, KnownLayout, Immutable, Unaligned, Copy, Clone)]
 #[repr(transparent)]
-struct NetworkEndianIpv6(zerocopy::byteorder::network_endian::U128);
+struct NetworkEndianIpv6(network_endian::U128);
 impl NetworkEndianIpv6 {
     #[inline]
     fn get(self) -> Ipv6Addr {
diff --git a/safekeeper/src/bin/safekeeper.rs b/safekeeper/src/bin/safekeeper.rs
index 000235f2f5..dd71420efb 100644
--- a/safekeeper/src/bin/safekeeper.rs
+++ b/safekeeper/src/bin/safekeeper.rs
@@ -226,11 +226,16 @@ struct Args {
     /// Path to the JWT auth token used to authenticate with other safekeepers.
     #[arg(long)]
     auth_token_path: Option<Utf8PathBuf>,
+
     /// Enable TLS in WAL service API.
     /// Does not force TLS: the client negotiates TLS usage during the handshake.
     /// Uses key and certificate from ssl_key_file/ssl_cert_file.
     #[arg(long)]
     enable_tls_wal_service_api: bool,
+
+    /// Run in development mode (disables security checks)
+    #[arg(long, help = "Run in development mode (disables security checks)")]
+    dev: bool,
 }
 
 // Like PathBufValueParser, but allows empty string.
diff --git a/storage_controller/migrations/2025-03-18-103700_timeline_imports/down.sql b/storage_controller/migrations/2025-03-18-103700_timeline_imports/down.sql
new file mode 100644
index 0000000000..4e7ae74ce2
--- /dev/null
+++ b/storage_controller/migrations/2025-03-18-103700_timeline_imports/down.sql
@@ -0,0 +1 @@
+DROP TABLE timeline_imports;
diff --git a/storage_controller/migrations/2025-03-18-103700_timeline_imports/up.sql b/storage_controller/migrations/2025-03-18-103700_timeline_imports/up.sql
new file mode 100644
index 0000000000..27741c439d
--- /dev/null
+++ b/storage_controller/migrations/2025-03-18-103700_timeline_imports/up.sql
@@ -0,0 +1,6 @@
+CREATE TABLE timeline_imports (
+  tenant_id VARCHAR NOT NULL,
+  timeline_id VARCHAR NOT NULL,
+  shard_statuses JSONB NOT NULL,
+  PRIMARY KEY(tenant_id, timeline_id)
+);
diff --git a/storage_controller/src/http.rs b/storage_controller/src/http.rs
index fb4530d0d2..649113b8ce 100644
--- a/storage_controller/src/http.rs
+++ b/storage_controller/src/http.rs
@@ -30,7 +30,9 @@ use pageserver_api::models::{
     TimelineArchivalConfigRequest, TimelineCreateRequest,
 };
 use pageserver_api::shard::TenantShardId;
-use pageserver_api::upcall_api::{ReAttachRequest, ValidateRequest};
+use pageserver_api::upcall_api::{
+    PutTimelineImportStatusRequest, ReAttachRequest, ValidateRequest,
+};
 use pageserver_client::{BlockUnblock, mgmt_api};
 use routerify::Middleware;
 use tokio_util::sync::CancellationToken;
@@ -70,6 +72,7 @@ impl HttpState {
             neon_metrics: NeonMetrics::new(build_info),
             allowlist_routes: &[
                 "/status",
+                "/live",
                 "/ready",
                 "/metrics",
                 "/profile/cpu",
@@ -154,6 +157,28 @@ async fn handle_validate(req: Request<Body>) -> Result<Response<Body>, ApiError>
     json_response(StatusCode::OK, state.service.validate(validate_req).await?)
 }
 
+async fn handle_put_timeline_import_status(req: Request<Body>) -> Result<Response<Body>, ApiError> {
+    check_permissions(&req, Scope::GenerationsApi)?;
+
+    let mut req = match maybe_forward(req).await {
+        ForwardOutcome::Forwarded(res) => {
+            return res;
+        }
+        ForwardOutcome::NotForwarded(req) => req,
+    };
+
+    let put_req = json_request::<PutTimelineImportStatusRequest>(&mut req).await?;
+
+    let state = get_state(&req);
+    json_response(
+        StatusCode::OK,
+        state
+            .service
+            .handle_timeline_shard_import_progress_upcall(put_req)
+            .await?,
+    )
+}
+
 /// Call into this before attaching a tenant to a pageserver, to acquire a generation number
 /// (in the real control plane this is unnecessary, because the same program is managing
 ///  generation numbers and doing attachments).
@@ -1236,16 +1261,8 @@ async fn handle_step_down(req: Request<Body>) -> Result<Response<Body>, ApiError
         ForwardOutcome::NotForwarded(req) => req,
     };
 
-    // Spawn a background task: once we start stepping down, we must finish: if the client drops
-    // their request we should avoid stopping in some part-stepped-down state.
-    let handle = tokio::spawn(async move {
-        let state = get_state(&req);
-        state.service.step_down().await
-    });
-
-    let result = handle
-        .await
-        .map_err(|e| ApiError::InternalServerError(e.into()))?;
+    let state = get_state(&req);
+    let result = state.service.step_down().await;
 
     json_response(StatusCode::OK, result)
 }
@@ -1377,6 +1394,8 @@ async fn handle_reconcile_all(req: Request<Body>) -> Result<Response<Body>, ApiE
 }
 
 /// Status endpoint is just used for checking that our HTTP listener is up
+///
+/// This serves as our k8s startup probe.
 async fn handle_status(req: Request<Body>) -> Result<Response<Body>, ApiError> {
     match maybe_forward(req).await {
         ForwardOutcome::Forwarded(res) => {
@@ -1388,6 +1407,30 @@ async fn handle_status(req: Request<Body>) -> Result<Response<Body>, ApiError> {
     json_response(StatusCode::OK, ())
 }
 
+/// Liveness endpoint indicates that this storage controller is in a state
+/// where it can fulfill it's responsibilties. Namely, startup has finished
+/// and it is the current leader.
+///
+/// This serves as our k8s liveness probe.
+async fn handle_live(req: Request<Body>) -> Result<Response<Body>, ApiError> {
+    let req = match maybe_forward(req).await {
+        ForwardOutcome::Forwarded(res) => {
+            return res;
+        }
+        ForwardOutcome::NotForwarded(req) => req,
+    };
+
+    let state = get_state(&req);
+    let live = state.service.startup_complete.is_ready()
+        && state.service.get_leadership_status() == LeadershipStatus::Leader;
+
+    if live {
+        json_response(StatusCode::OK, ())
+    } else {
+        json_response(StatusCode::SERVICE_UNAVAILABLE, ())
+    }
+}
+
 /// Readiness endpoint indicates when we're done doing startup I/O (e.g. reconciling
 /// with remote pageserver nodes).  This is intended for use as a kubernetes readiness probe.
 async fn handle_ready(req: Request<Body>) -> Result<Response<Body>, ApiError> {
@@ -1721,6 +1764,7 @@ async fn maybe_forward(req: Request<Body>) -> ForwardOutcome {
     const NOT_FOR_FORWARD: &[&str] = &[
         "/control/v1/step_down",
         "/status",
+        "/live",
         "/ready",
         "/metrics",
         "/profile/cpu",
@@ -1945,6 +1989,9 @@ pub fn make_router(
         .get("/status", |r| {
             named_request_span(r, handle_status, RequestName("status"))
         })
+        .get("/live", |r| {
+            named_request_span(r, handle_live, RequestName("live"))
+        })
         .get("/ready", |r| {
             named_request_span(r, handle_ready, RequestName("ready"))
         })
@@ -1961,6 +2008,13 @@ pub fn make_router(
         .post("/upcall/v1/validate", |r| {
             named_request_span(r, handle_validate, RequestName("upcall_v1_validate"))
         })
+        .post("/upcall/v1/timeline_import_status", |r| {
+            named_request_span(
+                r,
+                handle_put_timeline_import_status,
+                RequestName("upcall_v1_timeline_import_status"),
+            )
+        })
         // Test/dev/debug endpoints
         .post("/debug/v1/attach-hook", |r| {
             named_request_span(r, handle_attach_hook, RequestName("debug_v1_attach_hook"))
diff --git a/storage_controller/src/leadership.rs b/storage_controller/src/leadership.rs
index 39c28d60a9..048f752db5 100644
--- a/storage_controller/src/leadership.rs
+++ b/storage_controller/src/leadership.rs
@@ -43,6 +43,19 @@ impl Leadership {
         &self,
     ) -> Result<(Option<ControllerPersistence>, Option<GlobalObservedState>)> {
         let leader = self.current_leader().await?;
+
+        if leader.as_ref().map(|l| &l.address)
+            == self
+                .config
+                .address_for_peers
+                .as_ref()
+                .map(Uri::to_string)
+                .as_ref()
+        {
+            // We already are the current leader. This is a restart.
+            return Ok((leader, None));
+        }
+
         let leader_step_down_state = if let Some(ref leader) = leader {
             if self.config.start_as_candidate {
                 self.request_step_down(leader).await
diff --git a/storage_controller/src/lib.rs b/storage_controller/src/lib.rs
index 5f2c081927..a9ec511431 100644
--- a/storage_controller/src/lib.rs
+++ b/storage_controller/src/lib.rs
@@ -23,6 +23,7 @@ mod scheduler;
 mod schema;
 pub mod service;
 mod tenant_shard;
+mod timeline_import;
 
 #[derive(Ord, PartialOrd, Eq, PartialEq, Copy, Clone, Serialize)]
 struct Sequence(u64);
diff --git a/storage_controller/src/pageserver_client.rs b/storage_controller/src/pageserver_client.rs
index d14fc35b39..554ca375f5 100644
--- a/storage_controller/src/pageserver_client.rs
+++ b/storage_controller/src/pageserver_client.rs
@@ -212,6 +212,21 @@ impl PageserverClient {
         )
     }
 
+    pub(crate) async fn timeline_detail(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+    ) -> Result<TimelineInfo> {
+        measured_request!(
+            "timeline_detail",
+            crate::metrics::Method::Get,
+            &self.node_id_label,
+            self.inner
+                .timeline_detail(tenant_shard_id, timeline_id)
+                .await
+        )
+    }
+
     pub(crate) async fn tenant_shard_split(
         &self,
         tenant_shard_id: TenantShardId,
diff --git a/storage_controller/src/peer_client.rs b/storage_controller/src/peer_client.rs
index 604d1024ba..bae2fed096 100644
--- a/storage_controller/src/peer_client.rs
+++ b/storage_controller/src/peer_client.rs
@@ -55,9 +55,12 @@ impl ResponseErrorMessageExt for reqwest::Response {
     }
 }
 
-#[derive(Serialize, Deserialize, Debug, Default)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub(crate) struct GlobalObservedState(pub(crate) HashMap<TenantShardId, ObservedState>);
 
+const STEP_DOWN_RETRIES: u32 = 8;
+const STEP_DOWN_TIMEOUT: Duration = Duration::from_secs(1);
+
 impl PeerClient {
     pub(crate) fn new(http_client: reqwest::Client, uri: Uri, jwt: Option<String>) -> Self {
         Self {
@@ -76,7 +79,7 @@ impl PeerClient {
             req
         };
 
-        let req = req.timeout(Duration::from_secs(2));
+        let req = req.timeout(STEP_DOWN_TIMEOUT);
 
         let res = req
             .send()
@@ -94,8 +97,7 @@ impl PeerClient {
     }
 
     /// Request the peer to step down and return its current observed state
-    /// All errors are retried with exponential backoff for a maximum of 4 attempts.
-    /// Assuming all retries are performed, the function times out after roughly 4 seconds.
+    /// All errors are re-tried
     pub(crate) async fn step_down(
         &self,
         cancel: &CancellationToken,
@@ -104,7 +106,7 @@ impl PeerClient {
             || self.request_step_down(),
             |_e| false,
             2,
-            4,
+            STEP_DOWN_RETRIES,
             "Send step down request",
             cancel,
         )
diff --git a/storage_controller/src/persistence.rs b/storage_controller/src/persistence.rs
index a413bba3c9..64a8846a9d 100644
--- a/storage_controller/src/persistence.rs
+++ b/storage_controller/src/persistence.rs
@@ -22,7 +22,7 @@ use pageserver_api::controller_api::{
     AvailabilityZone, MetadataHealthRecord, NodeSchedulingPolicy, PlacementPolicy,
     SafekeeperDescribeResponse, ShardSchedulingPolicy, SkSchedulingPolicy,
 };
-use pageserver_api::models::TenantConfig;
+use pageserver_api::models::{ShardImportStatus, TenantConfig};
 use pageserver_api::shard::{
     ShardConfigError, ShardCount, ShardIdentity, ShardNumber, ShardStripeSize, TenantShardId,
 };
@@ -40,6 +40,9 @@ use crate::metrics::{
     DatabaseQueryErrorLabelGroup, DatabaseQueryLatencyLabelGroup, METRICS_REGISTRY,
 };
 use crate::node::Node;
+use crate::timeline_import::{
+    TimelineImport, TimelineImportUpdateError, TimelineImportUpdateFollowUp,
+};
 const MIGRATIONS: EmbeddedMigrations = embed_migrations!("./migrations");
 
 /// ## What do we store?
@@ -127,6 +130,10 @@ pub(crate) enum DatabaseOperation {
     RemoveTimelineReconcile,
     ListTimelineReconcile,
     ListTimelineReconcileStartup,
+    InsertTimelineImport,
+    UpdateTimelineImport,
+    DeleteTimelineImport,
+    ListTimelineImports,
 }
 
 #[must_use]
@@ -1614,6 +1621,158 @@ impl Persistence {
 
         Ok(())
     }
+
+    pub(crate) async fn insert_timeline_import(
+        &self,
+        import: TimelineImportPersistence,
+    ) -> DatabaseResult<bool> {
+        self.with_measured_conn(DatabaseOperation::InsertTimelineImport, move |conn| {
+            Box::pin({
+                let import = import.clone();
+                async move {
+                    let inserted = diesel::insert_into(crate::schema::timeline_imports::table)
+                        .values(import)
+                        .execute(conn)
+                        .await?;
+                    Ok(inserted == 1)
+                }
+            })
+        })
+        .await
+    }
+
+    pub(crate) async fn list_complete_timeline_imports(
+        &self,
+    ) -> DatabaseResult<Vec<TimelineImport>> {
+        use crate::schema::timeline_imports::dsl;
+        let persistent = self
+            .with_measured_conn(DatabaseOperation::ListTimelineImports, move |conn| {
+                Box::pin(async move {
+                    let from_db: Vec<TimelineImportPersistence> =
+                        dsl::timeline_imports.load(conn).await?;
+                    Ok(from_db)
+                })
+            })
+            .await?;
+
+        let imports: Result<Vec<TimelineImport>, _> = persistent
+            .into_iter()
+            .map(TimelineImport::from_persistent)
+            .collect();
+        match imports {
+            Ok(ok) => Ok(ok
+                .into_iter()
+                .filter(|import| import.is_complete())
+                .collect()),
+            Err(err) => Err(DatabaseError::Logical(format!(
+                "failed to deserialize import: {err}"
+            ))),
+        }
+    }
+
+    pub(crate) async fn delete_timeline_import(
+        &self,
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> DatabaseResult<()> {
+        use crate::schema::timeline_imports::dsl;
+
+        self.with_measured_conn(DatabaseOperation::DeleteTimelineImport, move |conn| {
+            Box::pin(async move {
+                diesel::delete(crate::schema::timeline_imports::table)
+                    .filter(
+                        dsl::tenant_id
+                            .eq(tenant_id.to_string())
+                            .and(dsl::timeline_id.eq(timeline_id.to_string())),
+                    )
+                    .execute(conn)
+                    .await?;
+
+                Ok(())
+            })
+        })
+        .await
+    }
+
+    /// Idempotently update the status of one shard for an ongoing timeline import
+    ///
+    /// If the update was persisted to the database, then the current state of the
+    /// import is returned to the caller. In case of logical errors a bespoke
+    /// [`TimelineImportUpdateError`] instance is returned. Other database errors
+    /// are covered by the outer [`DatabaseError`].
+    pub(crate) async fn update_timeline_import(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+        shard_status: ShardImportStatus,
+    ) -> DatabaseResult<Result<Option<TimelineImport>, TimelineImportUpdateError>> {
+        use crate::schema::timeline_imports::dsl;
+
+        self.with_measured_conn(DatabaseOperation::UpdateTimelineImport, move |conn| {
+            Box::pin({
+                let shard_status = shard_status.clone();
+                async move {
+                    // Load the current state from the database
+                    let mut from_db: Vec<TimelineImportPersistence> = dsl::timeline_imports
+                        .filter(
+                            dsl::tenant_id
+                                .eq(tenant_shard_id.tenant_id.to_string())
+                                .and(dsl::timeline_id.eq(timeline_id.to_string())),
+                        )
+                        .load(conn)
+                        .await?;
+
+                    assert!(from_db.len() <= 1);
+
+                    let mut status = match from_db.pop() {
+                        Some(some) => TimelineImport::from_persistent(some).unwrap(),
+                        None => {
+                            return Ok(Err(TimelineImportUpdateError::ImportNotFound {
+                                tenant_id: tenant_shard_id.tenant_id,
+                                timeline_id,
+                            }));
+                        }
+                    };
+
+                    // Perform the update in-memory
+                    let follow_up = match status.update(tenant_shard_id.to_index(), shard_status) {
+                        Ok(ok) => ok,
+                        Err(err) => {
+                            return Ok(Err(err));
+                        }
+                    };
+
+                    let new_persistent = status.to_persistent();
+
+                    // Write back if required (in the same transaction)
+                    match follow_up {
+                        TimelineImportUpdateFollowUp::Persist => {
+                            let updated = diesel::update(dsl::timeline_imports)
+                                .filter(
+                                    dsl::tenant_id
+                                        .eq(tenant_shard_id.tenant_id.to_string())
+                                        .and(dsl::timeline_id.eq(timeline_id.to_string())),
+                                )
+                                .set(dsl::shard_statuses.eq(new_persistent.shard_statuses))
+                                .execute(conn)
+                                .await?;
+
+                            if updated != 1 {
+                                return Ok(Err(TimelineImportUpdateError::ImportNotFound {
+                                    tenant_id: tenant_shard_id.tenant_id,
+                                    timeline_id,
+                                }));
+                            }
+
+                            Ok(Ok(Some(status)))
+                        }
+                        TimelineImportUpdateFollowUp::None => Ok(Ok(None)),
+                    }
+                }
+            })
+        })
+        .await
+    }
 }
 
 pub(crate) fn load_certs() -> anyhow::Result<Arc<rustls::RootCertStore>> {
@@ -2171,3 +2330,11 @@ impl ToSql<diesel::sql_types::VarChar, Pg> for SafekeeperTimelineOpKind {
             .map_err(Into::into)
     }
 }
+
+#[derive(Serialize, Deserialize, Queryable, Selectable, Insertable, Eq, PartialEq, Clone)]
+#[diesel(table_name = crate::schema::timeline_imports)]
+pub(crate) struct TimelineImportPersistence {
+    pub(crate) tenant_id: String,
+    pub(crate) timeline_id: String,
+    pub(crate) shard_statuses: serde_json::Value,
+}
diff --git a/storage_controller/src/schema.rs b/storage_controller/src/schema.rs
index 9b36376fcb..20be9bb5ca 100644
--- a/storage_controller/src/schema.rs
+++ b/storage_controller/src/schema.rs
@@ -76,6 +76,14 @@ diesel::table! {
     }
 }
 
+diesel::table! {
+    timeline_imports (tenant_id, timeline_id) {
+        tenant_id -> Varchar,
+        timeline_id -> Varchar,
+        shard_statuses -> Jsonb,
+    }
+}
+
 diesel::table! {
     use diesel::sql_types::*;
     use super::sql_types::PgLsn;
@@ -99,5 +107,6 @@ diesel::allow_tables_to_appear_in_same_query!(
     safekeeper_timeline_pending_ops,
     safekeepers,
     tenant_shards,
+    timeline_imports,
     timelines,
 );
diff --git a/storage_controller/src/service.rs b/storage_controller/src/service.rs
index 860fc4f6ab..7e5e3fd8f4 100644
--- a/storage_controller/src/service.rs
+++ b/storage_controller/src/service.rs
@@ -11,7 +11,7 @@ use std::num::NonZeroU32;
 use std::ops::{Deref, DerefMut};
 use std::path::PathBuf;
 use std::str::FromStr;
-use std::sync::Arc;
+use std::sync::{Arc, OnceLock};
 use std::time::{Duration, Instant, SystemTime};
 
 use anyhow::Context;
@@ -40,14 +40,14 @@ use pageserver_api::models::{
     TenantLocationConfigResponse, TenantShardLocation, TenantShardSplitRequest,
     TenantShardSplitResponse, TenantSorting, TenantTimeTravelRequest,
     TimelineArchivalConfigRequest, TimelineCreateRequest, TimelineCreateResponseStorcon,
-    TimelineInfo, TopTenantShardItem, TopTenantShardsRequest,
+    TimelineInfo, TimelineState, TopTenantShardItem, TopTenantShardsRequest,
 };
 use pageserver_api::shard::{
     DEFAULT_STRIPE_SIZE, ShardCount, ShardIdentity, ShardNumber, ShardStripeSize, TenantShardId,
 };
 use pageserver_api::upcall_api::{
-    ReAttachRequest, ReAttachResponse, ReAttachResponseTenant, ValidateRequest, ValidateResponse,
-    ValidateResponseTenant,
+    PutTimelineImportStatusRequest, ReAttachRequest, ReAttachResponse, ReAttachResponseTenant,
+    ValidateRequest, ValidateResponse, ValidateResponseTenant,
 };
 use pageserver_client::{BlockUnblock, mgmt_api};
 use reqwest::{Certificate, StatusCode};
@@ -97,6 +97,7 @@ use crate::tenant_shard::{
     ReconcileNeeded, ReconcileResult, ReconcileWaitError, ReconcilerStatus, ReconcilerWaiter,
     ScheduleOptimization, ScheduleOptimizationAction, TenantShard,
 };
+use crate::timeline_import::{ShardImportStatuses, TimelineImport, UpcallClient};
 
 const WAITER_FILL_DRAIN_POLL_TIMEOUT: Duration = Duration::from_millis(500);
 
@@ -523,6 +524,9 @@ pub struct Service {
 
     /// HTTP client with proper CA certs.
     http_client: reqwest::Client,
+
+    /// Handle for the step down background task if one was ever requested
+    step_down_barrier: OnceLock<tokio::sync::watch::Receiver<Option<GlobalObservedState>>>,
 }
 
 impl From<ReconcileWaitError> for ApiError {
@@ -874,6 +878,22 @@ impl Service {
             });
         }
 
+        // Fetch the list of completed imports and attempt to finalize them in the background.
+        // This handles the case where the previous storage controller instance shut down
+        // whilst finalizing imports.
+        let complete_imports = self.persistence.list_complete_timeline_imports().await;
+        match complete_imports {
+            Ok(ok) => {
+                tokio::task::spawn({
+                    let finalize_imports_self = self.clone();
+                    async move { finalize_imports_self.finalize_timeline_imports(ok).await }
+                });
+            }
+            Err(err) => {
+                tracing::error!("Could not retrieve completed imports from database: {err}");
+            }
+        }
+
         tracing::info!(
             "Startup complete, spawned {reconcile_tasks} reconciliation tasks ({shard_count} shards total)"
         );
@@ -1744,6 +1764,7 @@ impl Service {
             tenant_op_locks: Default::default(),
             node_op_locks: Default::default(),
             http_client,
+            step_down_barrier: Default::default(),
         });
 
         let result_task_this = this.clone();
@@ -3732,11 +3753,14 @@ impl Service {
         create_req: TimelineCreateRequest,
     ) -> Result<TimelineCreateResponseStorcon, ApiError> {
         let safekeepers = self.config.timelines_onto_safekeepers;
+        let timeline_id = create_req.new_timeline_id;
+
         tracing::info!(
+            mode=%create_req.mode_tag(),
             %safekeepers,
             "Creating timeline {}/{}",
             tenant_id,
-            create_req.new_timeline_id,
+            timeline_id,
         );
 
         let _tenant_lock = trace_shared_lock(
@@ -3746,15 +3770,62 @@ impl Service {
         )
         .await;
         failpoint_support::sleep_millis_async!("tenant-create-timeline-shared-lock");
-        let create_mode = create_req.mode.clone();
+        let is_import = create_req.is_import();
 
         let timeline_info = self
             .tenant_timeline_create_pageservers(tenant_id, create_req)
             .await?;
 
-        let safekeepers = if safekeepers {
+        let selected_safekeepers = if is_import {
+            let shards = {
+                let locked = self.inner.read().unwrap();
+                locked
+                    .tenants
+                    .range(TenantShardId::tenant_range(tenant_id))
+                    .map(|(ts_id, _)| ts_id.to_index())
+                    .collect::<Vec<_>>()
+            };
+
+            if !shards
+                .iter()
+                .map(|shard_index| shard_index.shard_count)
+                .all_equal()
+            {
+                return Err(ApiError::InternalServerError(anyhow::anyhow!(
+                    "Inconsistent shard count"
+                )));
+            }
+
+            let import = TimelineImport {
+                tenant_id,
+                timeline_id,
+                shard_statuses: ShardImportStatuses::new(shards),
+            };
+
+            let inserted = self
+                .persistence
+                .insert_timeline_import(import.to_persistent())
+                .await
+                .context("timeline import insert")
+                .map_err(ApiError::InternalServerError)?;
+
+            match inserted {
+                true => {
+                    tracing::info!(%tenant_id, %timeline_id, "Inserted timeline import");
+                }
+                false => {
+                    tracing::info!(%tenant_id, %timeline_id, "Timeline import entry already present");
+                }
+            }
+
+            None
+        } else if safekeepers {
+            // Note that we do not support creating the timeline on the safekeepers
+            // for imported timelines. The `start_lsn` of the timeline is not known
+            // until the import finshes.
+            // https://github.com/neondatabase/neon/issues/11569
             let res = self
-                .tenant_timeline_create_safekeepers(tenant_id, &timeline_info, create_mode)
+                .tenant_timeline_create_safekeepers(tenant_id, &timeline_info)
                 .instrument(tracing::info_span!("timeline_create_safekeepers", %tenant_id, timeline_id=%timeline_info.timeline_id))
                 .await?;
             Some(res)
@@ -3764,10 +3835,174 @@ impl Service {
 
         Ok(TimelineCreateResponseStorcon {
             timeline_info,
-            safekeepers,
+            safekeepers: selected_safekeepers,
         })
     }
 
+    pub(crate) async fn handle_timeline_shard_import_progress_upcall(
+        self: &Arc<Self>,
+        req: PutTimelineImportStatusRequest,
+    ) -> Result<(), ApiError> {
+        let res = self
+            .persistence
+            .update_timeline_import(req.tenant_shard_id, req.timeline_id, req.status)
+            .await;
+        let timeline_import = match res {
+            Ok(Ok(Some(timeline_import))) => timeline_import,
+            Ok(Ok(None)) => {
+                // Idempotency: we've already seen and handled this update.
+                return Ok(());
+            }
+            Ok(Err(logical_err)) => {
+                return Err(logical_err.into());
+            }
+            Err(db_err) => {
+                return Err(db_err.into());
+            }
+        };
+
+        tracing::info!(
+            tenant_id=%req.tenant_shard_id.tenant_id,
+            timeline_id=%req.timeline_id,
+            shard_id=%req.tenant_shard_id.shard_slug(),
+            "Updated timeline import status to: {timeline_import:?}");
+
+        if timeline_import.is_complete() {
+            tokio::task::spawn({
+                let this = self.clone();
+                async move { this.finalize_timeline_import(timeline_import).await }
+            });
+        }
+
+        Ok(())
+    }
+
+    #[instrument(skip_all, fields(
+        tenant_id=%import.tenant_id,
+        shard_id=%import.timeline_id,
+    ))]
+    async fn finalize_timeline_import(
+        self: &Arc<Self>,
+        import: TimelineImport,
+    ) -> anyhow::Result<()> {
+        tracing::info!("Finalizing timeline import");
+
+        pausable_failpoint!("timeline-import-pre-cplane-notification");
+
+        let import_failed = import.completion_error().is_some();
+
+        if !import_failed {
+            loop {
+                if self.cancel.is_cancelled() {
+                    anyhow::bail!("Shut down requested while finalizing import");
+                }
+
+                let active = self.timeline_active_on_all_shards(&import).await?;
+
+                match active {
+                    true => {
+                        tracing::info!("Timeline became active on all shards");
+                        break;
+                    }
+                    false => {
+                        tracing::info!("Timeline not active on all shards yet");
+
+                        tokio::select! {
+                            _ = self.cancel.cancelled() => {
+                                anyhow::bail!("Shut down requested while finalizing import");
+                            },
+                            _ = tokio::time::sleep(Duration::from_secs(5)) => {}
+                        };
+                    }
+                }
+            }
+        }
+
+        tracing::info!(%import_failed, "Notifying cplane of import completion");
+
+        let client = UpcallClient::new(self.get_config(), self.cancel.child_token());
+        client.notify_import_complete(&import).await?;
+
+        if let Err(err) = self
+            .persistence
+            .delete_timeline_import(import.tenant_id, import.timeline_id)
+            .await
+        {
+            tracing::warn!("Failed to delete timeline import entry from database: {err}");
+        }
+
+        // TODO(vlad): Timeline creations in import mode do not return a correct initdb lsn,
+        // so we can't create the timeline on the safekeepers. Fix by moving creation here.
+        // https://github.com/neondatabase/neon/issues/11569
+        tracing::info!(%import_failed, "Timeline import complete");
+
+        Ok(())
+    }
+
+    async fn finalize_timeline_imports(self: &Arc<Self>, imports: Vec<TimelineImport>) {
+        futures::future::join_all(
+            imports
+                .into_iter()
+                .map(|import| self.finalize_timeline_import(import)),
+        )
+        .await;
+    }
+
+    async fn timeline_active_on_all_shards(
+        self: &Arc<Self>,
+        import: &TimelineImport,
+    ) -> anyhow::Result<bool> {
+        let targets = {
+            let locked = self.inner.read().unwrap();
+            let mut targets = Vec::new();
+
+            for (tenant_shard_id, shard) in locked
+                .tenants
+                .range(TenantShardId::tenant_range(import.tenant_id))
+            {
+                if !import
+                    .shard_statuses
+                    .0
+                    .contains_key(&tenant_shard_id.to_index())
+                {
+                    anyhow::bail!("Shard layout change detected on completion");
+                }
+
+                if let Some(node_id) = shard.intent.get_attached() {
+                    let node = locked
+                        .nodes
+                        .get(node_id)
+                        .expect("Pageservers may not be deleted while referenced");
+                    targets.push((*tenant_shard_id, node.clone()));
+                } else {
+                    return Ok(false);
+                }
+            }
+
+            targets
+        };
+
+        let results = self
+            .tenant_for_shards_api(
+                targets,
+                |tenant_shard_id, client| async move {
+                    client
+                        .timeline_detail(tenant_shard_id, import.timeline_id)
+                        .await
+                },
+                1,
+                1,
+                SHORT_RECONCILE_TIMEOUT,
+                &self.cancel,
+            )
+            .await;
+
+        Ok(results.into_iter().all(|res| match res {
+            Ok(info) => info.state == TimelineState::Active,
+            Err(_) => false,
+        }))
+    }
+
     pub(crate) async fn tenant_timeline_archival_config(
         &self,
         tenant_id: TenantId,
@@ -8677,27 +8912,59 @@ impl Service {
         self.inner.read().unwrap().get_leadership_status()
     }
 
-    pub(crate) async fn step_down(&self) -> GlobalObservedState {
+    /// Handler for step down requests
+    ///
+    /// Step down runs in separate task since once it's called it should
+    /// be driven to completion. Subsequent requests will wait on the same
+    /// step down task.
+    pub(crate) async fn step_down(self: &Arc<Self>) -> GlobalObservedState {
+        let handle = self.step_down_barrier.get_or_init(|| {
+            let step_down_self = self.clone();
+            let (tx, rx) = tokio::sync::watch::channel::<Option<GlobalObservedState>>(None);
+            tokio::spawn(async move {
+                let state = step_down_self.step_down_task().await;
+                tx.send(Some(state))
+                    .expect("Task Arc<Service> keeps receiver alive");
+            });
+
+            rx
+        });
+
+        handle
+            .clone()
+            .wait_for(|observed_state| observed_state.is_some())
+            .await
+            .expect("Task Arc<Service> keeps sender alive")
+            .deref()
+            .clone()
+            .expect("Checked above")
+    }
+
+    async fn step_down_task(&self) -> GlobalObservedState {
         tracing::info!("Received step down request from peer");
         failpoint_support::sleep_millis_async!("sleep-on-step-down-handling");
 
         self.inner.write().unwrap().step_down();
 
-        // Wait for reconciliations to stop, or terminate this process if they
-        // fail to stop in time (this indicates a bug in shutdown)
-        tokio::select! {
-            _ = self.stop_reconciliations(StopReconciliationsReason::SteppingDown) => {
-                tracing::info!("Reconciliations stopped, proceeding with step down");
-            }
-            _ = async {
-                failpoint_support::sleep_millis_async!("step-down-delay-timeout");
-                tokio::time::sleep(Duration::from_secs(10)).await
-            } => {
-                tracing::warn!("Step down timed out while waiting for reconciliation gate, terminating process");
+        let stop_reconciliations =
+            self.stop_reconciliations(StopReconciliationsReason::SteppingDown);
+        let mut stop_reconciliations = std::pin::pin!(stop_reconciliations);
 
-                // The caller may proceed to act as leader when it sees this request fail: reduce the chance
-                // of a split-brain situation by terminating this controller instead of leaving it up in a partially-shut-down state.
-                std::process::exit(1);
+        let started_at = Instant::now();
+
+        // Wait for reconciliations to stop and warn if that's taking a long time
+        loop {
+            tokio::select! {
+                _ = &mut stop_reconciliations => {
+                    tracing::info!("Reconciliations stopped, proceeding with step down");
+                    break;
+                }
+                _ = tokio::time::sleep(Duration::from_secs(10)) => {
+                    tracing::warn!(
+                        elapsed_sec=%started_at.elapsed().as_secs(),
+                        "Stopping reconciliations during step down is taking too long"
+                    );
+                }
             }
         }
 
diff --git a/storage_controller/src/service/safekeeper_service.rs b/storage_controller/src/service/safekeeper_service.rs
index 088b3c4741..5eecf0d415 100644
--- a/storage_controller/src/service/safekeeper_service.rs
+++ b/storage_controller/src/service/safekeeper_service.rs
@@ -15,7 +15,7 @@ use http_utils::error::ApiError;
 use pageserver_api::controller_api::{
     SafekeeperDescribeResponse, SkSchedulingPolicy, TimelineImportRequest,
 };
-use pageserver_api::models::{self, SafekeeperInfo, SafekeepersInfo, TimelineInfo};
+use pageserver_api::models::{SafekeeperInfo, SafekeepersInfo, TimelineInfo};
 use safekeeper_api::membership::{MemberSet, SafekeeperId};
 use tokio::task::JoinSet;
 use tokio_util::sync::CancellationToken;
@@ -207,7 +207,6 @@ impl Service {
         self: &Arc<Self>,
         tenant_id: TenantId,
         timeline_info: &TimelineInfo,
-        create_mode: models::TimelineCreateRequestMode,
     ) -> Result<SafekeepersInfo, ApiError> {
         let timeline_id = timeline_info.timeline_id;
         let pg_version = timeline_info.pg_version * 10000;
@@ -217,15 +216,8 @@ impl Service {
         // previously existed as on retries in theory endpoint might have
         // already written some data and advanced last_record_lsn, while we want
         // safekeepers to have consistent start_lsn.
-        let start_lsn = match create_mode {
-            models::TimelineCreateRequestMode::Bootstrap { .. } => timeline_info.last_record_lsn,
-            models::TimelineCreateRequestMode::Branch { .. } => timeline_info.last_record_lsn,
-            models::TimelineCreateRequestMode::ImportPgdata { .. } => {
-                return Err(ApiError::InternalServerError(anyhow::anyhow!(
-                    "import pgdata doesn't specify the start lsn, aborting creation on safekeepers"
-                )))?;
-            }
-        };
+        let start_lsn = timeline_info.last_record_lsn;
+
         // Choose initial set of safekeepers respecting affinity
         let sks = self.safekeepers_for_new_timeline().await?;
         let sks_persistence = sks.iter().map(|sk| sk.id.0 as i64).collect::<Vec<_>>();
diff --git a/storage_controller/src/timeline_import.rs b/storage_controller/src/timeline_import.rs
new file mode 100644
index 0000000000..b6dd4b252e
--- /dev/null
+++ b/storage_controller/src/timeline_import.rs
@@ -0,0 +1,260 @@
+use std::time::Duration;
+use std::{collections::HashMap, str::FromStr};
+
+use http_utils::error::ApiError;
+use reqwest::Method;
+use serde::{Deserialize, Serialize};
+
+use pageserver_api::models::ShardImportStatus;
+use tokio_util::sync::CancellationToken;
+use utils::{
+    id::{TenantId, TimelineId},
+    shard::ShardIndex,
+};
+
+use crate::{persistence::TimelineImportPersistence, service::Config};
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+pub(crate) struct ShardImportStatuses(pub(crate) HashMap<ShardIndex, ShardImportStatus>);
+
+impl ShardImportStatuses {
+    pub(crate) fn new(shards: Vec<ShardIndex>) -> Self {
+        ShardImportStatuses(
+            shards
+                .into_iter()
+                .map(|ts_id| (ts_id, ShardImportStatus::InProgress))
+                .collect(),
+        )
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct TimelineImport {
+    pub(crate) tenant_id: TenantId,
+    pub(crate) timeline_id: TimelineId,
+    pub(crate) shard_statuses: ShardImportStatuses,
+}
+
+pub(crate) enum TimelineImportUpdateFollowUp {
+    Persist,
+    None,
+}
+
+pub(crate) enum TimelineImportUpdateError {
+    ImportNotFound {
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    },
+    MismatchedShards,
+    UnexpectedUpdate,
+}
+
+impl From<TimelineImportUpdateError> for ApiError {
+    fn from(err: TimelineImportUpdateError) -> ApiError {
+        match err {
+            TimelineImportUpdateError::ImportNotFound {
+                tenant_id,
+                timeline_id,
+            } => ApiError::NotFound(
+                anyhow::anyhow!("Import for {tenant_id}/{timeline_id} not found").into(),
+            ),
+            TimelineImportUpdateError::MismatchedShards => {
+                ApiError::InternalServerError(anyhow::anyhow!(
+                    "Import shards do not match update request, likely a shard split happened during import, this is a bug"
+                ))
+            }
+            TimelineImportUpdateError::UnexpectedUpdate => {
+                ApiError::InternalServerError(anyhow::anyhow!("Update request is unexpected"))
+            }
+        }
+    }
+}
+
+impl TimelineImport {
+    pub(crate) fn from_persistent(persistent: TimelineImportPersistence) -> anyhow::Result<Self> {
+        let tenant_id = TenantId::from_str(persistent.tenant_id.as_str())?;
+        let timeline_id = TimelineId::from_str(persistent.timeline_id.as_str())?;
+        let shard_statuses = serde_json::from_value(persistent.shard_statuses)?;
+
+        Ok(TimelineImport {
+            tenant_id,
+            timeline_id,
+            shard_statuses,
+        })
+    }
+
+    pub(crate) fn to_persistent(&self) -> TimelineImportPersistence {
+        TimelineImportPersistence {
+            tenant_id: self.tenant_id.to_string(),
+            timeline_id: self.timeline_id.to_string(),
+            shard_statuses: serde_json::to_value(self.shard_statuses.clone()).unwrap(),
+        }
+    }
+
+    pub(crate) fn update(
+        &mut self,
+        shard: ShardIndex,
+        status: ShardImportStatus,
+    ) -> Result<TimelineImportUpdateFollowUp, TimelineImportUpdateError> {
+        use std::collections::hash_map::Entry::*;
+
+        match self.shard_statuses.0.entry(shard) {
+            Occupied(mut occ) => {
+                let crnt = occ.get_mut();
+                if *crnt == status {
+                    Ok(TimelineImportUpdateFollowUp::None)
+                } else if crnt.is_terminal() && *crnt != status {
+                    Err(TimelineImportUpdateError::UnexpectedUpdate)
+                } else {
+                    *crnt = status;
+                    Ok(TimelineImportUpdateFollowUp::Persist)
+                }
+            }
+            Vacant(_) => Err(TimelineImportUpdateError::MismatchedShards),
+        }
+    }
+
+    pub(crate) fn is_complete(&self) -> bool {
+        self.shard_statuses
+            .0
+            .values()
+            .all(|status| status.is_terminal())
+    }
+
+    pub(crate) fn completion_error(&self) -> Option<String> {
+        assert!(self.is_complete());
+
+        let shard_errors: HashMap<_, _> = self
+            .shard_statuses
+            .0
+            .iter()
+            .filter_map(|(shard, status)| {
+                if let ShardImportStatus::Error(err) = status {
+                    Some((*shard, err.clone()))
+                } else {
+                    None
+                }
+            })
+            .collect();
+
+        if shard_errors.is_empty() {
+            None
+        } else {
+            Some(serde_json::to_string(&shard_errors).unwrap())
+        }
+    }
+}
+
+pub(crate) struct UpcallClient {
+    authorization_header: Option<String>,
+    client: reqwest::Client,
+    cancel: CancellationToken,
+    base_url: String,
+}
+
+const IMPORT_COMPLETE_REQUEST_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[derive(Serialize, Deserialize, Debug)]
+struct ImportCompleteRequest {
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+    error: Option<String>,
+}
+
+impl UpcallClient {
+    pub(crate) fn new(config: &Config, cancel: CancellationToken) -> Self {
+        let authorization_header = config
+            .control_plane_jwt_token
+            .clone()
+            .map(|jwt| format!("Bearer {}", jwt));
+
+        let client = reqwest::ClientBuilder::new()
+            .timeout(IMPORT_COMPLETE_REQUEST_TIMEOUT)
+            .build()
+            .expect("Failed to construct HTTP client");
+
+        let base_url = config
+            .control_plane_url
+            .clone()
+            .expect("must be configured");
+
+        Self {
+            authorization_header,
+            client,
+            cancel,
+            base_url,
+        }
+    }
+
+    /// Notify control plane of a completed import
+    ///
+    /// This method guarantees at least once delivery semantics assuming
+    /// eventual cplane availability. The cplane API is idempotent.
+    pub(crate) async fn notify_import_complete(
+        &self,
+        import: &TimelineImport,
+    ) -> anyhow::Result<()> {
+        let endpoint = if self.base_url.ends_with('/') {
+            format!("{}import_complete", self.base_url)
+        } else {
+            format!("{}/import_complete", self.base_url)
+        };
+
+        tracing::info!("Endpoint is {endpoint}");
+
+        let request = self
+            .client
+            .request(Method::PUT, endpoint)
+            .json(&ImportCompleteRequest {
+                tenant_id: import.tenant_id,
+                timeline_id: import.timeline_id,
+                error: import.completion_error(),
+            })
+            .timeout(IMPORT_COMPLETE_REQUEST_TIMEOUT);
+
+        let request = if let Some(auth) = &self.authorization_header {
+            request.header(reqwest::header::AUTHORIZATION, auth)
+        } else {
+            request
+        };
+
+        const RETRY_DELAY: Duration = Duration::from_secs(1);
+        let mut attempt = 1;
+
+        loop {
+            if self.cancel.is_cancelled() {
+                return Err(anyhow::anyhow!(
+                    "Shutting down while notifying cplane of import completion"
+                ));
+            }
+
+            match request.try_clone().unwrap().send().await {
+                Ok(response) if response.status().is_success() => {
+                    return Ok(());
+                }
+                Ok(response) => {
+                    tracing::warn!(
+                        "Import complete notification failed with status {}, attempt {}",
+                        response.status(),
+                        attempt
+                    );
+                }
+                Err(e) => {
+                    tracing::warn!(
+                        "Import complete notification failed with error: {}, attempt {}",
+                        e,
+                        attempt
+                    );
+                }
+            }
+
+            tokio::select! {
+                _ = tokio::time::sleep(RETRY_DELAY) => {}
+                _ = self.cancel.cancelled() => {
+                    return Err(anyhow::anyhow!("Shutting down while notifying cplane of import completion"));
+                }
+            }
+            attempt += 1;
+        }
+    }
+}
diff --git a/storage_scrubber/Cargo.toml b/storage_scrubber/Cargo.toml
index 7f6544b894..1c8b0e9f4a 100644
--- a/storage_scrubber/Cargo.toml
+++ b/storage_scrubber/Cargo.toml
@@ -5,8 +5,6 @@ edition = "2024"
 license.workspace = true
 
 [dependencies]
-aws-config.workspace = true
-aws-sdk-s3.workspace = true
 either.workspace = true
 anyhow.workspace = true
 hex.workspace = true
diff --git a/storage_scrubber/src/lib.rs b/storage_scrubber/src/lib.rs
index 071f0b9756..25a157f108 100644
--- a/storage_scrubber/src/lib.rs
+++ b/storage_scrubber/src/lib.rs
@@ -12,14 +12,9 @@ pub mod tenant_snapshot;
 
 use std::env;
 use std::fmt::Display;
-use std::sync::Arc;
 use std::time::{Duration, SystemTime};
 
 use anyhow::Context;
-use aws_config::retry::{RetryConfigBuilder, RetryMode};
-use aws_sdk_s3::Client;
-use aws_sdk_s3::config::Region;
-use aws_sdk_s3::error::DisplayErrorContext;
 use camino::{Utf8Path, Utf8PathBuf};
 use clap::ValueEnum;
 use futures::{Stream, StreamExt};
@@ -28,7 +23,7 @@ use pageserver::tenant::remote_timeline_client::{remote_tenant_path, remote_time
 use pageserver_api::shard::TenantShardId;
 use remote_storage::{
     DownloadOpts, GenericRemoteStorage, Listing, ListingMode, RemotePath, RemoteStorageConfig,
-    RemoteStorageKind, S3Config,
+    RemoteStorageKind, VersionId,
 };
 use reqwest::Url;
 use serde::{Deserialize, Serialize};
@@ -351,21 +346,6 @@ pub fn init_logging(file_name: &str) -> Option<WorkerGuard> {
     }
 }
 
-async fn init_s3_client(bucket_region: Region) -> Client {
-    let mut retry_config_builder = RetryConfigBuilder::new();
-
-    retry_config_builder
-        .set_max_attempts(Some(3))
-        .set_mode(Some(RetryMode::Adaptive));
-
-    let config = aws_config::defaults(aws_config::BehaviorVersion::v2024_03_28())
-        .region(bucket_region)
-        .retry_config(retry_config_builder.build())
-        .load()
-        .await;
-    Client::new(&config)
-}
-
 fn default_prefix_in_bucket(node_kind: NodeKind) -> &'static str {
     match node_kind {
         NodeKind::Pageserver => "pageserver/v1/",
@@ -385,23 +365,6 @@ fn make_root_target(desc_str: String, prefix_in_bucket: String, node_kind: NodeK
     }
 }
 
-async fn init_remote_s3(
-    bucket_config: S3Config,
-    node_kind: NodeKind,
-) -> anyhow::Result<(Arc<Client>, RootTarget)> {
-    let bucket_region = Region::new(bucket_config.bucket_region);
-    let s3_client = Arc::new(init_s3_client(bucket_region).await);
-    let default_prefix = default_prefix_in_bucket(node_kind).to_string();
-
-    let s3_root = make_root_target(
-        bucket_config.bucket_name,
-        bucket_config.prefix_in_bucket.unwrap_or(default_prefix),
-        node_kind,
-    );
-
-    Ok((s3_client, s3_root))
-}
-
 async fn init_remote(
     mut storage_config: BucketConfig,
     node_kind: NodeKind,
@@ -499,7 +462,7 @@ async fn list_objects_with_retries(
                     remote_client.bucket_name().unwrap_or_default(),
                     s3_target.prefix_in_bucket,
                     s3_target.delimiter,
-                    DisplayErrorContext(e),
+                    e,
                 );
                 let backoff_time = 1 << trial.min(5);
                 tokio::time::sleep(Duration::from_secs(backoff_time)).await;
@@ -549,14 +512,18 @@ async fn download_object_with_retries(
     anyhow::bail!("Failed to download objects with key {key} {MAX_RETRIES} times")
 }
 
-async fn download_object_to_file_s3(
-    s3_client: &Client,
-    bucket_name: &str,
-    key: &str,
-    version_id: Option<&str>,
+async fn download_object_to_file(
+    remote_storage: &GenericRemoteStorage,
+    key: &RemotePath,
+    version_id: Option<VersionId>,
     local_path: &Utf8Path,
 ) -> anyhow::Result<()> {
+    let opts = DownloadOpts {
+        version_id: version_id.clone(),
+        ..Default::default()
+    };
     let tmp_path = Utf8PathBuf::from(format!("{local_path}.tmp"));
+    let cancel = CancellationToken::new();
     for _ in 0..MAX_RETRIES {
         tokio::fs::remove_file(&tmp_path)
             .await
@@ -566,28 +533,24 @@ async fn download_object_to_file_s3(
             .await
             .context("Opening output file")?;
 
-        let request = s3_client.get_object().bucket(bucket_name).key(key);
+        let res = remote_storage.download(key, &opts, &cancel).await;
 
-        let request = match version_id {
-            Some(version_id) => request.version_id(version_id),
-            None => request,
-        };
-
-        let response_stream = match request.send().await {
+        let download = match res {
             Ok(response) => response,
             Err(e) => {
                 error!(
-                    "Failed to download object for key {key} version {}: {e:#}",
-                    version_id.unwrap_or("")
+                    "Failed to download object for key {key} version {:?}: {e:#}",
+                    &version_id.as_ref().unwrap_or(&VersionId(String::new()))
                 );
                 tokio::time::sleep(Duration::from_secs(1)).await;
                 continue;
             }
         };
 
-        let mut read_stream = response_stream.body.into_async_read();
+        //response_stream.download_stream
 
-        tokio::io::copy(&mut read_stream, &mut file).await?;
+        let mut body = tokio_util::io::StreamReader::new(download.download_stream);
+        tokio::io::copy(&mut body, &mut file).await?;
 
         tokio::fs::rename(&tmp_path, local_path).await?;
         return Ok(());
diff --git a/storage_scrubber/src/tenant_snapshot.rs b/storage_scrubber/src/tenant_snapshot.rs
index e17409c20e..24231e32fc 100644
--- a/storage_scrubber/src/tenant_snapshot.rs
+++ b/storage_scrubber/src/tenant_snapshot.rs
@@ -1,31 +1,30 @@
 use std::collections::HashMap;
-use std::sync::Arc;
 
 use anyhow::Context;
 use async_stream::stream;
-use aws_sdk_s3::Client;
 use camino::Utf8PathBuf;
 use futures::{StreamExt, TryStreamExt};
 use pageserver::tenant::IndexPart;
 use pageserver::tenant::remote_timeline_client::index::LayerFileMetadata;
+use pageserver::tenant::remote_timeline_client::remote_layer_path;
 use pageserver::tenant::storage_layer::LayerName;
 use pageserver_api::shard::TenantShardId;
-use remote_storage::{GenericRemoteStorage, S3Config};
+use remote_storage::GenericRemoteStorage;
+use tokio_util::sync::CancellationToken;
 use utils::generation::Generation;
 use utils::id::TenantId;
 
 use crate::checks::{BlobDataParseResult, RemoteTimelineBlobData, list_timeline_blobs};
 use crate::metadata_stream::{stream_tenant_shards, stream_tenant_timelines};
 use crate::{
-    BucketConfig, NodeKind, RootTarget, TenantShardTimelineId, download_object_to_file_s3,
-    init_remote, init_remote_s3,
+    BucketConfig, NodeKind, RootTarget, TenantShardTimelineId, download_object_to_file, init_remote,
 };
 
 pub struct SnapshotDownloader {
-    s3_client: Arc<Client>,
-    s3_root: RootTarget,
+    remote_client: GenericRemoteStorage,
+    #[allow(dead_code)]
+    target: RootTarget,
     bucket_config: BucketConfig,
-    bucket_config_s3: S3Config,
     tenant_id: TenantId,
     output_path: Utf8PathBuf,
     concurrency: usize,
@@ -38,17 +37,13 @@ impl SnapshotDownloader {
         output_path: Utf8PathBuf,
         concurrency: usize,
     ) -> anyhow::Result<Self> {
-        let bucket_config_s3 = match &bucket_config.0.storage {
-            remote_storage::RemoteStorageKind::AwsS3(config) => config.clone(),
-            _ => panic!("only S3 configuration is supported for snapshot downloading"),
-        };
-        let (s3_client, s3_root) =
-            init_remote_s3(bucket_config_s3.clone(), NodeKind::Pageserver).await?;
+        let (remote_client, target) =
+            init_remote(bucket_config.clone(), NodeKind::Pageserver).await?;
+
         Ok(Self {
-            s3_client,
-            s3_root,
+            remote_client,
+            target,
             bucket_config,
-            bucket_config_s3,
             tenant_id,
             output_path,
             concurrency,
@@ -61,6 +56,7 @@ impl SnapshotDownloader {
         layer_name: LayerName,
         layer_metadata: LayerFileMetadata,
     ) -> anyhow::Result<(LayerName, LayerFileMetadata)> {
+        let cancel = CancellationToken::new();
         // Note this is local as in a local copy of S3 data, not local as in the pageserver's local format.  They use
         // different layer names (remote-style has the generation suffix)
         let local_path = self.output_path.join(format!(
@@ -82,30 +78,27 @@ impl SnapshotDownloader {
         } else {
             tracing::debug!("{} requires download...", local_path);
 
-            let timeline_root = self.s3_root.timeline_root(&ttid);
-            let remote_layer_path = format!(
-                "{}{}{}",
-                timeline_root.prefix_in_bucket,
-                layer_name,
-                layer_metadata.generation.get_suffix()
+            let remote_path = remote_layer_path(
+                &ttid.tenant_shard_id.tenant_id,
+                &ttid.timeline_id,
+                layer_metadata.shard,
+                &layer_name,
+                layer_metadata.generation,
             );
+            let mode = remote_storage::ListingMode::NoDelimiter;
 
             // List versions: the object might be deleted.
             let versions = self
-                .s3_client
-                .list_object_versions()
-                .bucket(self.bucket_config_s3.bucket_name.clone())
-                .prefix(&remote_layer_path)
-                .send()
+                .remote_client
+                .list_versions(Some(&remote_path), mode, None, &cancel)
                 .await?;
-            let Some(version) = versions.versions.as_ref().and_then(|v| v.first()) else {
-                return Err(anyhow::anyhow!("No versions found for {remote_layer_path}"));
+            let Some(version) = versions.versions.first() else {
+                return Err(anyhow::anyhow!("No versions found for {remote_path}"));
             };
-            download_object_to_file_s3(
-                &self.s3_client,
-                &self.bucket_config_s3.bucket_name,
-                &remote_layer_path,
-                version.version_id.as_deref(),
+            download_object_to_file(
+                &self.remote_client,
+                &remote_path,
+                version.version_id().cloned(),
                 &local_path,
             )
             .await?;
diff --git a/test_runner/conftest.py b/test_runner/conftest.py
index 4b591d3316..3c67e2ca8f 100644
--- a/test_runner/conftest.py
+++ b/test_runner/conftest.py
@@ -16,4 +16,5 @@ pytest_plugins = (
     "fixtures.slow",
     "fixtures.reruns",
     "fixtures.fast_import",
+    "fixtures.pg_config",
 )
diff --git a/test_runner/fixtures/neon_cli.py b/test_runner/fixtures/neon_cli.py
index 80852b610b..b5d69b5ab6 100644
--- a/test_runner/fixtures/neon_cli.py
+++ b/test_runner/fixtures/neon_cli.py
@@ -417,14 +417,14 @@ class NeonLocalCli(AbstractNeonCli):
             cmd.append(f"--instance-id={instance_id}")
         return self.raw_cli(cmd)
 
-    def object_storage_start(self, timeout_in_seconds: int | None = None):
-        cmd = ["object-storage", "start"]
+    def endpoint_storage_start(self, timeout_in_seconds: int | None = None):
+        cmd = ["endpoint-storage", "start"]
         if timeout_in_seconds is not None:
             cmd.append(f"--start-timeout={timeout_in_seconds}s")
         return self.raw_cli(cmd)
 
-    def object_storage_stop(self, immediate: bool):
-        cmd = ["object-storage", "stop"]
+    def endpoint_storage_stop(self, immediate: bool):
+        cmd = ["endpoint-storage", "stop"]
         if immediate:
             cmd.extend(["-m", "immediate"])
         return self.raw_cli(cmd)
diff --git a/test_runner/fixtures/neon_fixtures.py b/test_runner/fixtures/neon_fixtures.py
index db2b68d082..48aa739ce4 100644
--- a/test_runner/fixtures/neon_fixtures.py
+++ b/test_runner/fixtures/neon_fixtures.py
@@ -1029,7 +1029,7 @@ class NeonEnvBuilder:
 
             self.env.broker.assert_no_errors()
 
-            self.env.object_storage.assert_no_errors()
+            self.env.endpoint_storage.assert_no_errors()
 
         try:
             self.overlay_cleanup_teardown()
@@ -1126,7 +1126,7 @@ class NeonEnv:
             pagectl_env_vars["RUST_LOG"] = self.rust_log_override
         self.pagectl = Pagectl(extra_env=pagectl_env_vars, binpath=self.neon_binpath)
 
-        self.object_storage = ObjectStorage(self)
+        self.endpoint_storage = EndpointStorage(self)
 
         # The URL for the pageserver to use as its control_plane_api config
         if config.storage_controller_port_override is not None:
@@ -1183,7 +1183,7 @@ class NeonEnv:
             },
             "safekeepers": [],
             "pageservers": [],
-            "object_storage": {"port": self.port_distributor.get_port()},
+            "endpoint_storage": {"port": self.port_distributor.get_port()},
             "generate_local_ssl_certs": self.generate_local_ssl_certs,
         }
 
@@ -1291,7 +1291,11 @@ class NeonEnv:
                             ps_cfg[key] = value
 
             if self.pageserver_virtual_file_io_mode is not None:
-                ps_cfg["virtual_file_io_mode"] = self.pageserver_virtual_file_io_mode
+                # TODO(christian): https://github.com/neondatabase/neon/issues/11598
+                if not config.test_may_use_compatibility_snapshot_binaries:
+                    ps_cfg["virtual_file_io_mode"] = self.pageserver_virtual_file_io_mode
+                else:
+                    log.info("ignoring virtual_file_io_mode parametrization for compatibility test")
 
             if self.pageserver_wal_receiver_protocol is not None:
                 key, value = PageserverWalReceiverProtocol.to_config_key_value(
@@ -1420,7 +1424,7 @@ class NeonEnv:
                 self.storage_controller.on_safekeeper_deploy(sk_id, body)
                 self.storage_controller.safekeeper_scheduling_policy(sk_id, "Active")
 
-        self.object_storage.start(timeout_in_seconds=timeout_in_seconds)
+        self.endpoint_storage.start(timeout_in_seconds=timeout_in_seconds)
 
     def stop(self, immediate=False, ps_assert_metric_no_errors=False, fail_on_endpoint_errors=True):
         """
@@ -1439,7 +1443,7 @@ class NeonEnv:
         except Exception as e:
             raise_later = e
 
-        self.object_storage.stop(immediate=immediate)
+        self.endpoint_storage.stop(immediate=immediate)
 
         # Stop storage controller before pageservers: we don't want it to spuriously
         # detect a pageserver "failure" during test teardown
@@ -2660,24 +2664,24 @@ class NeonStorageController(MetricsGetter, LogUtils):
         self.stop(immediate=True)
 
 
-class ObjectStorage(LogUtils):
+class EndpointStorage(LogUtils):
     def __init__(self, env: NeonEnv):
-        service_dir = env.repo_dir / "object_storage"
-        super().__init__(logfile=service_dir / "object_storage.log")
-        self.conf_path = service_dir / "object_storage.json"
+        service_dir = env.repo_dir / "endpoint_storage"
+        super().__init__(logfile=service_dir / "endpoint_storage.log")
+        self.conf_path = service_dir / "endpoint_storage.json"
         self.env = env
 
     def base_url(self):
         return json.loads(self.conf_path.read_text())["listen"]
 
     def start(self, timeout_in_seconds: int | None = None):
-        self.env.neon_cli.object_storage_start(timeout_in_seconds)
+        self.env.neon_cli.endpoint_storage_start(timeout_in_seconds)
 
     def stop(self, immediate: bool = False):
-        self.env.neon_cli.object_storage_stop(immediate)
+        self.env.neon_cli.endpoint_storage_stop(immediate)
 
     def assert_no_errors(self):
-        assert_no_errors(self.logfile, "object_storage", [])
+        assert_no_errors(self.logfile, "endpoint_storage", [])
 
 
 class NeonProxiedStorageController(NeonStorageController):
@@ -3380,6 +3384,9 @@ class VanillaPostgres(PgProtocol):
         """Return size of pgdatadir subdirectory in bytes."""
         return get_dir_size(self.pgdatadir / subdir)
 
+    def is_running(self) -> bool:
+        return self.running
+
     def __enter__(self) -> Self:
         return self
 
diff --git a/test_runner/fixtures/pg_config.py b/test_runner/fixtures/pg_config.py
new file mode 100644
index 0000000000..751aaf9759
--- /dev/null
+++ b/test_runner/fixtures/pg_config.py
@@ -0,0 +1,249 @@
+from __future__ import annotations
+
+import shlex
+from enum import StrEnum
+from pathlib import Path
+from typing import TYPE_CHECKING, cast, final
+
+import pytest
+
+if TYPE_CHECKING:
+    from collections.abc import Iterator
+    from typing import IO
+
+    from fixtures.neon_fixtures import PgBin
+
+
+@final
+class PgConfigKey(StrEnum):
+    BINDIR = "BINDIR"
+    DOCDIR = "DOCDIR"
+    HTMLDIR = "HTMLDIR"
+    INCLUDEDIR = "INCLUDEDIR"
+    PKGINCLUDEDIR = "PKGINCLUDEDIR"
+    INCLUDEDIR_SERVER = "INCLUDEDIR-SERVER"
+    LIBDIR = "LIBDIR"
+    PKGLIBDIR = "PKGLIBDIR"
+    LOCALEDIR = "LOCALEDIR"
+    MANDIR = "MANDIR"
+    SHAREDIR = "SHAREDIR"
+    SYSCONFDIR = "SYSCONFDIR"
+    PGXS = "PGXS"
+    CONFIGURE = "CONFIGURE"
+    CC = "CC"
+    CPPFLAGS = "CPPFLAGS"
+    CFLAGS = "CFLAGS"
+    CFLAGS_SL = "CFLAGS_SL"
+    LDFLAGS = "LDFLAGS"
+    LDFLAGS_EX = "LDFLAGS_EX"
+    LDFLAGS_SL = "LDFLAGS_SL"
+    LIBS = "LIBS"
+    VERSION = "VERSION"
+
+
+if TYPE_CHECKING:
+    # TODO: This could become a TypedDict if Python ever allows StrEnums to be
+    # keys.
+    PgConfig = dict[PgConfigKey, str | Path | list[str]]
+
+
+def __get_pg_config(pg_bin: PgBin) -> PgConfig:
+    """Get pg_config values by invoking the command"""
+
+    cmd = pg_bin.run_nonblocking(["pg_config"])
+    cmd.wait()
+    if cmd.returncode != 0:
+        pytest.exit("")
+    assert cmd.stdout
+
+    stdout = cast("IO[str]", cmd.stdout)
+
+    # Parse the output into a dictionary
+    values: PgConfig = {}
+    for line in stdout.readlines():
+        if "=" in line:
+            key, value = line.split("=", 1)
+            value = value.strip()
+            match PgConfigKey(key.strip()):
+                case (
+                    (
+                        PgConfigKey.CC
+                        | PgConfigKey.CPPFLAGS
+                        | PgConfigKey.CFLAGS
+                        | PgConfigKey.CFLAGS_SL
+                        | PgConfigKey.LDFLAGS
+                        | PgConfigKey.LDFLAGS_EX
+                        | PgConfigKey.LDFLAGS_SL
+                        | PgConfigKey.LIBS
+                    ) as k
+                ):
+                    values[k] = shlex.split(value)
+                case (
+                    (
+                        PgConfigKey.BINDIR
+                        | PgConfigKey.DOCDIR
+                        | PgConfigKey.HTMLDIR
+                        | PgConfigKey.INCLUDEDIR
+                        | PgConfigKey.PKGINCLUDEDIR
+                        | PgConfigKey.INCLUDEDIR_SERVER
+                        | PgConfigKey.LIBDIR
+                        | PgConfigKey.PKGLIBDIR
+                        | PgConfigKey.LOCALEDIR
+                        | PgConfigKey.MANDIR
+                        | PgConfigKey.SHAREDIR
+                        | PgConfigKey.SYSCONFDIR
+                        | PgConfigKey.PGXS
+                    ) as k
+                ):
+                    values[k] = Path(value)
+                case _ as k:
+                    values[k] = value
+
+    return values
+
+
+@pytest.fixture(scope="function")
+def pg_config(pg_bin: PgBin) -> Iterator[PgConfig]:
+    """Dictionary of all pg_config values from the system"""
+
+    yield __get_pg_config(pg_bin)
+
+
+@pytest.fixture(scope="function")
+def pg_config_bindir(pg_config: PgConfig) -> Iterator[Path]:
+    """BINDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.BINDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_docdir(pg_config: PgConfig) -> Iterator[Path]:
+    """DOCDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.DOCDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_htmldir(pg_config: PgConfig) -> Iterator[Path]:
+    """HTMLDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.HTMLDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_includedir(
+    pg_config: dict[PgConfigKey, str | Path | list[str]],
+) -> Iterator[Path]:
+    """INCLUDEDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.INCLUDEDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_pkgincludedir(pg_config: PgConfig) -> Iterator[Path]:
+    """PKGINCLUDEDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.PKGINCLUDEDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_includedir_server(pg_config: PgConfig) -> Iterator[Path]:
+    """INCLUDEDIR-SERVER value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.INCLUDEDIR_SERVER])
+
+
+@pytest.fixture(scope="function")
+def pg_config_libdir(pg_config: PgConfig) -> Iterator[Path]:
+    """LIBDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.LIBDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_pkglibdir(pg_config: PgConfig) -> Iterator[Path]:
+    """PKGLIBDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.PKGLIBDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_localedir(pg_config: PgConfig) -> Iterator[Path]:
+    """LOCALEDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.LOCALEDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_mandir(pg_config: PgConfig) -> Iterator[Path]:
+    """MANDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.MANDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_sharedir(pg_config: PgConfig) -> Iterator[Path]:
+    """SHAREDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.SHAREDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_sysconfdir(pg_config: PgConfig) -> Iterator[Path]:
+    """SYSCONFDIR value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.SYSCONFDIR])
+
+
+@pytest.fixture(scope="function")
+def pg_config_pgxs(pg_config: PgConfig) -> Iterator[Path]:
+    """PGXS value from pg_config"""
+    yield cast("Path", pg_config[PgConfigKey.PGXS])
+
+
+@pytest.fixture(scope="function")
+def pg_config_configure(pg_config: PgConfig) -> Iterator[str]:
+    """CONFIGURE value from pg_config"""
+    yield cast("str", pg_config[PgConfigKey.CONFIGURE])
+
+
+@pytest.fixture(scope="function")
+def pg_config_cc(pg_config: PgConfig) -> Iterator[list[str]]:
+    """CC value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.CC])
+
+
+@pytest.fixture(scope="function")
+def pg_config_cppflags(pg_config: PgConfig) -> Iterator[list[str]]:
+    """CPPFLAGS value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.CPPFLAGS])
+
+
+@pytest.fixture(scope="function")
+def pg_config_cflags(pg_config: PgConfig) -> Iterator[list[str]]:
+    """CFLAGS value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.CFLAGS])
+
+
+@pytest.fixture(scope="function")
+def pg_config_cflags_sl(pg_config: PgConfig) -> Iterator[list[str]]:
+    """CFLAGS_SL value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.CFLAGS_SL])
+
+
+@pytest.fixture(scope="function")
+def pg_config_ldflags(pg_config: PgConfig) -> Iterator[list[str]]:
+    """LDFLAGS value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.LDFLAGS])
+
+
+@pytest.fixture(scope="function")
+def pg_config_ldflags_ex(pg_config: PgConfig) -> Iterator[list[str]]:
+    """LDFLAGS_EX value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.LDFLAGS_EX])
+
+
+@pytest.fixture(scope="function")
+def pg_config_ldflags_sl(pg_config: PgConfig) -> Iterator[list[str]]:
+    """LDFLAGS_SL value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.LDFLAGS_SL])
+
+
+@pytest.fixture(scope="function")
+def pg_config_libs(pg_config: PgConfig) -> Iterator[list[str]]:
+    """LIBS value from pg_config"""
+    yield cast("list[str]", pg_config[PgConfigKey.LIBS])
+
+
+@pytest.fixture(scope="function")
+def pg_config_version(pg_config: PgConfig) -> Iterator[str]:
+    """VERSION value from pg_config"""
+    yield cast("str", pg_config[PgConfigKey.VERSION])
diff --git a/test_runner/performance/test_physical_replication.py b/test_runner/performance/test_physical_replication.py
index 16cdab155a..bdafa2d657 100644
--- a/test_runner/performance/test_physical_replication.py
+++ b/test_runner/performance/test_physical_replication.py
@@ -65,7 +65,7 @@ def test_ro_replica_lag(
     project = neon_api.create_project(pg_version)
     project_id = project["project"]["id"]
     log.info("Project ID: %s", project_id)
-    log.info("Primary endpoint ID: %s", project["project"]["endpoints"][0]["id"])
+    log.info("Primary endpoint ID: %s", project["endpoints"][0]["id"])
     neon_api.wait_for_operation_to_finish(project_id)
     error_occurred = False
     try:
@@ -198,7 +198,7 @@ def test_replication_start_stop(
     project = neon_api.create_project(pg_version)
     project_id = project["project"]["id"]
     log.info("Project ID: %s", project_id)
-    log.info("Primary endpoint ID: %s", project["project"]["endpoints"][0]["id"])
+    log.info("Primary endpoint ID: %s", project["endpoints"][0]["id"])
     neon_api.wait_for_operation_to_finish(project_id)
     try:
         branch_id = project["branch"]["id"]
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension/sql/test_extension--1.0.sql b/test_runner/regress/data/test_remote_extensions/test_extension/sql/test_extension--1.0.sql
deleted file mode 100644
index b51e3ed19f..0000000000
--- a/test_runner/regress/data/test_remote_extensions/test_extension/sql/test_extension--1.0.sql
+++ /dev/null
@@ -1,12 +0,0 @@
-\echo Use "CREATE EXTENSION test_extension" to load this file. \quit
-
-CREATE SCHEMA test_extension;
-
-CREATE FUNCTION test_extension.motd()
-RETURNS void
-IMMUTABLE LEAKPROOF PARALLEL SAFE
-AS $$
-BEGIN
-    RAISE NOTICE 'Have a great day';
-END;
-$$ LANGUAGE 'plpgsql';
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension/test_extension.control b/test_runner/regress/data/test_remote_extensions/test_extension/test_extension.control
deleted file mode 100644
index 826f643daf..0000000000
--- a/test_runner/regress/data/test_remote_extensions/test_extension/test_extension.control
+++ /dev/null
@@ -1 +0,0 @@
-comment = 'Test extension'
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension/sql/test_extension--1.0--1.1.sql b/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/sql/test_extension_sql_only--1.0--1.1.sql
similarity index 50%
rename from test_runner/regress/data/test_remote_extensions/test_extension/sql/test_extension--1.0--1.1.sql
rename to test_runner/regress/data/test_remote_extensions/test_extension_sql_only/sql/test_extension_sql_only--1.0--1.1.sql
index 1fb183dcae..d8d2a2dce7 100644
--- a/test_runner/regress/data/test_remote_extensions/test_extension/sql/test_extension--1.0--1.1.sql
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/sql/test_extension_sql_only--1.0--1.1.sql
@@ -1,6 +1,6 @@
-\echo Use "ALTER EXTENSION test_extension UPDATE TO '1.1'" to load this file. \quit
+\echo Use "ALTER EXTENSION test_extension_sql_only UPDATE TO '1.1'" to load this file. \quit
 
-CREATE FUNCTION test_extension.fun_fact()
+CREATE FUNCTION test_extension_sql_only.fun_fact()
 RETURNS void
 IMMUTABLE LEAKPROOF PARALLEL SAFE
 AS $$
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/sql/test_extension_sql_only--1.0.sql b/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/sql/test_extension_sql_only--1.0.sql
new file mode 100644
index 0000000000..a0a496b0cf
--- /dev/null
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/sql/test_extension_sql_only--1.0.sql
@@ -0,0 +1,12 @@
+\echo Use "CREATE EXTENSION test_extension_sql_only" to load this file. \quit
+
+CREATE SCHEMA test_extension_sql_only;
+
+CREATE FUNCTION test_extension_sql_only.motd()
+RETURNS void
+IMMUTABLE LEAKPROOF PARALLEL SAFE
+AS $$
+BEGIN
+    RAISE NOTICE 'Have a great day';
+END;
+$$ LANGUAGE 'plpgsql';
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/test_extension_sql_only.control b/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/test_extension_sql_only.control
new file mode 100644
index 0000000000..f66546431a
--- /dev/null
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_sql_only/test_extension_sql_only.control
@@ -0,0 +1 @@
+comment = 'Test extension SQL only'
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/sql/test_extension_with_lib--1.0--1.1.sql b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/sql/test_extension_with_lib--1.0--1.1.sql
new file mode 100644
index 0000000000..733ed66994
--- /dev/null
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/sql/test_extension_with_lib--1.0--1.1.sql
@@ -0,0 +1,6 @@
+\echo Use "ALTER EXTENSION test_extension_with_lib UPDATE TO '1.1'" to load this file. \quit
+
+CREATE FUNCTION test_extension_with_lib.fun_fact()
+RETURNS void
+IMMUTABLE LEAKPROOF PARALLEL SAFE
+AS 'MODULE_PATHNAME', 'fun_fact' LANGUAGE C;
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/sql/test_extension_with_lib--1.0.sql b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/sql/test_extension_with_lib--1.0.sql
new file mode 100644
index 0000000000..5fd0350aae
--- /dev/null
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/sql/test_extension_with_lib--1.0.sql
@@ -0,0 +1,8 @@
+\echo Use "CREATE EXTENSION test_extension_with_lib" to load this file. \quit
+
+CREATE SCHEMA test_extension_with_lib;
+
+CREATE FUNCTION test_extension_with_lib.motd()
+RETURNS void
+IMMUTABLE LEAKPROOF PARALLEL SAFE
+AS 'MODULE_PATHNAME', 'motd' LANGUAGE C;
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/src/test_extension_with_lib.c b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/src/test_extension_with_lib.c
new file mode 100644
index 0000000000..8feca627ab
--- /dev/null
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/src/test_extension_with_lib.c
@@ -0,0 +1,34 @@
+#include <postgres.h>
+
+#include <fmgr.h>
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(motd);
+PG_FUNCTION_INFO_V1(fun_fact);
+
+/* Old versions of Postgres didn't pre-declare this in fmgr.h */
+#if PG_MAJORVERSION_NUM <= 15
+void _PG_init(void);
+#endif
+
+void
+_PG_init(void)
+{
+}
+
+Datum
+motd(PG_FUNCTION_ARGS)
+{
+    elog(NOTICE, "Have a great day");
+
+    PG_RETURN_VOID();
+}
+
+Datum
+fun_fact(PG_FUNCTION_ARGS)
+{
+    elog(NOTICE, "Neon has a melting point of -246.08 C");
+
+    PG_RETURN_VOID();
+}
diff --git a/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/test_extension_with_lib.control b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/test_extension_with_lib.control
new file mode 100644
index 0000000000..322f2bbe7b
--- /dev/null
+++ b/test_runner/regress/data/test_remote_extensions/test_extension_with_lib/test_extension_with_lib.control
@@ -0,0 +1,2 @@
+comment = 'Test extension with lib'
+module_pathname = '$libdir/test_extension_with_lib'
diff --git a/test_runner/regress/test_compute_monitor.py b/test_runner/regress/test_compute_monitor.py
new file mode 100644
index 0000000000..c0cc9a6e3b
--- /dev/null
+++ b/test_runner/regress/test_compute_monitor.py
@@ -0,0 +1,70 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from fixtures.metrics import parse_metrics
+from fixtures.utils import wait_until
+
+if TYPE_CHECKING:
+    from fixtures.neon_fixtures import NeonEnv
+
+
+def test_compute_monitor(neon_simple_env: NeonEnv):
+    """
+    Test that compute_ctl can detect Postgres going down (unresponsive) and
+    reconnect when it comes back online. Also check that the downtime metrics
+    are properly emitted.
+    """
+    TEST_DB = "test_compute_monitor"
+
+    env = neon_simple_env
+    endpoint = env.endpoints.create_start("main")
+
+    # Check that default postgres database is present
+    with endpoint.cursor() as cursor:
+        cursor.execute("SELECT datname FROM pg_database WHERE datname = 'postgres'")
+        catalog_db = cursor.fetchone()
+        assert catalog_db is not None
+        assert len(catalog_db) == 1
+
+        # Create a new database
+        cursor.execute(f"CREATE DATABASE {TEST_DB}")
+
+    # Drop database 'postgres'
+    with endpoint.cursor(dbname=TEST_DB) as cursor:
+        # Use FORCE to terminate all connections to the database
+        cursor.execute("DROP DATABASE postgres WITH (FORCE)")
+
+    client = endpoint.http_client()
+
+    def check_metrics_down():
+        raw_metrics = client.metrics()
+        metrics = parse_metrics(raw_metrics)
+        compute_pg_current_downtime_ms = metrics.query_all("compute_pg_current_downtime_ms")
+        assert len(compute_pg_current_downtime_ms) == 1
+        assert compute_pg_current_downtime_ms[0].value > 0
+        compute_pg_downtime_ms_total = metrics.query_all("compute_pg_downtime_ms_total")
+        assert len(compute_pg_downtime_ms_total) == 1
+        assert compute_pg_downtime_ms_total[0].value > 0
+
+    wait_until(check_metrics_down)
+
+    # Recreate postgres database
+    with endpoint.cursor(dbname=TEST_DB) as cursor:
+        cursor.execute("CREATE DATABASE postgres")
+
+    # Current downtime should reset to 0, but not total downtime
+    def check_metrics_up():
+        raw_metrics = client.metrics()
+        metrics = parse_metrics(raw_metrics)
+        compute_pg_current_downtime_ms = metrics.query_all("compute_pg_current_downtime_ms")
+        assert len(compute_pg_current_downtime_ms) == 1
+        assert compute_pg_current_downtime_ms[0].value == 0
+        compute_pg_downtime_ms_total = metrics.query_all("compute_pg_downtime_ms_total")
+        assert len(compute_pg_downtime_ms_total) == 1
+        assert compute_pg_downtime_ms_total[0].value > 0
+
+    wait_until(check_metrics_up)
+
+    # Just a sanity check that we log the downtime info
+    endpoint.log_contains("downtime_info")
diff --git a/test_runner/regress/test_download_extensions.py b/test_runner/regress/test_download_extensions.py
index a81d55e57b..3b6c94a268 100644
--- a/test_runner/regress/test_download_extensions.py
+++ b/test_runner/regress/test_download_extensions.py
@@ -4,12 +4,17 @@ import os
 import platform
 import shutil
 import tarfile
-from typing import TYPE_CHECKING
+from enum import StrEnum
+from pathlib import Path
+from typing import TYPE_CHECKING, cast, final
 
 import pytest
 import zstandard
 from fixtures.log_helper import log
 from fixtures.metrics import parse_metrics
+from fixtures.paths import BASE_DIR
+from fixtures.pg_config import PgConfigKey
+from fixtures.utils import subprocess_capture
 from werkzeug.wrappers.response import Response
 
 if TYPE_CHECKING:
@@ -20,6 +25,7 @@ if TYPE_CHECKING:
     from fixtures.neon_fixtures import (
         NeonEnvBuilder,
     )
+    from fixtures.pg_config import PgConfig
     from fixtures.pg_version import PgVersion
     from pytest_httpserver import HTTPServer
     from werkzeug.wrappers.request import Request
@@ -46,46 +52,108 @@ def neon_env_builder_local(
     return neon_env_builder
 
 
+@final
+class RemoteExtension(StrEnum):
+    SQL_ONLY = "test_extension_sql_only"
+    WITH_LIB = "test_extension_with_lib"
+
+    @property
+    def compressed_tarball_name(self) -> str:
+        return f"{self.tarball_name}.zst"
+
+    @property
+    def control_file_name(self) -> str:
+        return f"{self}.control"
+
+    @property
+    def directory(self) -> Path:
+        return BASE_DIR / "test_runner" / "regress" / "data" / "test_remote_extensions" / self
+
+    @property
+    def shared_library_name(self) -> str:
+        return f"{self}.so"
+
+    @property
+    def tarball_name(self) -> str:
+        return f"{self}.tar"
+
+    def archive_route(self, build_tag: str, arch: str, pg_version: PgVersion) -> str:
+        return f"{build_tag}/{arch}/v{pg_version}/extensions/{self.compressed_tarball_name}"
+
+    def build(self, pg_config: PgConfig, output_dir: Path) -> None:
+        if self is not RemoteExtension.WITH_LIB:
+            return
+
+        cmd: list[str] = [
+            *cast("list[str]", pg_config[PgConfigKey.CC]),
+            *cast("list[str]", pg_config[PgConfigKey.CPPFLAGS]),
+            *["-I", str(cast("Path", pg_config[PgConfigKey.INCLUDEDIR_SERVER]))],
+            *cast("list[str]", pg_config[PgConfigKey.CFLAGS]),
+            *cast("list[str]", pg_config[PgConfigKey.CFLAGS_SL]),
+            *cast("list[str]", pg_config[PgConfigKey.LDFLAGS_EX]),
+            *cast("list[str]", pg_config[PgConfigKey.LDFLAGS_SL]),
+            "-shared",
+            *["-o", str(output_dir / self.shared_library_name)],
+            str(self.directory / "src" / f"{self}.c"),
+        ]
+
+        subprocess_capture(output_dir, cmd, check=True)
+
+    def control_file_contents(self) -> str:
+        with open(self.directory / self.control_file_name, encoding="utf-8") as f:
+            return f.read()
+
+    def files(self, output_dir: Path) -> dict[Path, str]:
+        files = {
+            # self.directory / self.control_file_name: f"share/extension/{self.control_file_name}",
+            self.directory / "sql" / f"{self}--1.0.sql": f"share/extension/{self}--1.0.sql",
+            self.directory
+            / "sql"
+            / f"{self}--1.0--1.1.sql": f"share/extension/{self}--1.0--1.1.sql",
+        }
+
+        if self is RemoteExtension.WITH_LIB:
+            files[output_dir / self.shared_library_name] = f"lib/{self.shared_library_name}"
+
+        return files
+
+    def package(self, output_dir: Path) -> Path:
+        tarball = output_dir / self.tarball_name
+        with tarfile.open(tarball, "x") as tarf:
+            for file, arcname in self.files(output_dir).items():
+                tarf.add(file, arcname=arcname)
+
+        return tarball
+
+    def remove(self, output_dir: Path, pg_version: PgVersion) -> None:
+        for file in self.files(output_dir).values():
+            if file.startswith("share/extension"):
+                file = f"share/postgresql/extension/{os.path.basename(file)}"
+            if file.startswith("lib"):
+                file = f"lib/postgresql/{os.path.basename(file)}"
+            (output_dir / "pg_install" / f"v{pg_version}" / file).unlink()
+
+
+@pytest.mark.parametrize(
+    "extension",
+    (RemoteExtension.SQL_ONLY, RemoteExtension.WITH_LIB),
+    ids=["sql_only", "with_lib"],
+)
 def test_remote_extensions(
     httpserver: HTTPServer,
     neon_env_builder_local: NeonEnvBuilder,
     httpserver_listen_address: ListenAddress,
     test_output_dir: Path,
-    base_dir: Path,
     pg_version: PgVersion,
+    pg_config: PgConfig,
+    extension: RemoteExtension,
 ):
     # Setup a mock nginx S3 gateway which will return our test extension.
     (host, port) = httpserver_listen_address
     extensions_endpoint = f"http://{host}:{port}/pg-ext-s3-gateway"
 
-    build_tag = os.environ.get("BUILD_TAG", "latest")
-
-    # We have decided to use the Go naming convention due to Kubernetes.
-    arch = platform.machine()
-    match arch:
-        case "aarch64":
-            arch = "arm64"
-        case "x86_64":
-            arch = "amd64"
-        case _:
-            pass
-
-    archive_route = f"{build_tag}/{arch}/v{pg_version}/extensions/test_extension.tar.zst"
-    tarball = test_output_dir / "test_extension.tar"
-    extension_dir = (
-        base_dir / "test_runner" / "regress" / "data" / "test_remote_extensions" / "test_extension"
-    )
-
-    # Create tarball
-    with tarfile.open(tarball, "x") as tarf:
-        tarf.add(
-            extension_dir / "sql" / "test_extension--1.0.sql",
-            arcname="share/extension/test_extension--1.0.sql",
-        )
-        tarf.add(
-            extension_dir / "sql" / "test_extension--1.0--1.1.sql",
-            arcname="share/extension/test_extension--1.0--1.1.sql",
-        )
+    extension.build(pg_config, test_output_dir)
+    tarball = extension.package(test_output_dir)
 
     def handler(request: Request) -> Response:
         log.info(f"request: {request}")
@@ -104,8 +172,19 @@ def test_remote_extensions(
             direct_passthrough=True,
         )
 
+    # We have decided to use the Go naming convention due to Kubernetes.
+    arch = platform.machine()
+    match arch:
+        case "aarch64":
+            arch = "arm64"
+        case "x86_64":
+            arch = "amd64"
+        case _:
+            pass
+
     httpserver.expect_request(
-        f"/pg-ext-s3-gateway/{archive_route}", method="GET"
+        f"/pg-ext-s3-gateway/{extension.archive_route(build_tag=os.environ.get('BUILD_TAG', 'latest'), arch=arch, pg_version=pg_version)}",
+        method="GET",
     ).respond_with_handler(handler)
 
     # Start a compute node with remote_extension spec
@@ -114,21 +193,18 @@ def test_remote_extensions(
     env.create_branch("test_remote_extensions")
     endpoint = env.endpoints.create("test_remote_extensions")
 
-    with open(extension_dir / "test_extension.control", encoding="utf-8") as f:
-        control_data = f.read()
-
     # mock remote_extensions spec
     spec: dict[str, Any] = {
-        "public_extensions": ["test_extension"],
+        "public_extensions": [extension],
         "custom_extensions": None,
         "library_index": {
-            "test_extension": "test_extension",
+            extension: extension,
         },
         "extension_data": {
-            "test_extension": {
+            extension: {
                 "archive_path": "",
                 "control_data": {
-                    "test_extension.control": control_data,
+                    extension.control_file_name: extension.control_file_contents(),
                 },
             },
         },
@@ -141,8 +217,8 @@ def test_remote_extensions(
     with endpoint.connect() as conn:
         with conn.cursor() as cur:
             # Check that appropriate files were downloaded
-            cur.execute("CREATE EXTENSION test_extension VERSION '1.0'")
-            cur.execute("SELECT test_extension.motd()")
+            cur.execute(f"CREATE EXTENSION {extension} VERSION '1.0'")
+            cur.execute(f"SELECT {extension}.motd()")
 
     httpserver.check()
 
@@ -153,7 +229,7 @@ def test_remote_extensions(
     remote_ext_requests = metrics.query_all(
         "compute_ctl_remote_ext_requests_total",
         # Check that we properly report the filename in the metrics
-        {"filename": "test_extension.tar.zst"},
+        {"filename": extension.compressed_tarball_name},
     )
     assert len(remote_ext_requests) == 1
     for sample in remote_ext_requests:
@@ -162,20 +238,7 @@ def test_remote_extensions(
     endpoint.stop()
 
     # Remove the extension files to force a redownload of the extension.
-    for file in (
-        "test_extension.control",
-        "test_extension--1.0.sql",
-        "test_extension--1.0--1.1.sql",
-    ):
-        (
-            test_output_dir
-            / "pg_install"
-            / f"v{pg_version}"
-            / "share"
-            / "postgresql"
-            / "extension"
-            / file
-        ).unlink()
+    extension.remove(test_output_dir, pg_version)
 
     endpoint.start(remote_ext_config=extensions_endpoint)
 
@@ -183,8 +246,8 @@ def test_remote_extensions(
     with endpoint.connect() as conn:
         with conn.cursor() as cur:
             # Check that appropriate files were downloaded
-            cur.execute("ALTER EXTENSION test_extension UPDATE TO '1.1'")
-            cur.execute("SELECT test_extension.fun_fact()")
+            cur.execute(f"ALTER EXTENSION {extension} UPDATE TO '1.1'")
+            cur.execute(f"SELECT {extension}.fun_fact()")
 
     # Check that we properly recorded downloads in the metrics
     client = endpoint.http_client()
@@ -193,7 +256,7 @@ def test_remote_extensions(
     remote_ext_requests = metrics.query_all(
         "compute_ctl_remote_ext_requests_total",
         # Check that we properly report the filename in the metrics
-        {"filename": "test_extension.tar.zst"},
+        {"filename": extension.compressed_tarball_name},
     )
     assert len(remote_ext_requests) == 1
     for sample in remote_ext_requests:
diff --git a/test_runner/regress/test_object_storage.py b/test_runner/regress/test_endpoint_storage.py
similarity index 93%
rename from test_runner/regress/test_object_storage.py
rename to test_runner/regress/test_endpoint_storage.py
index 0b1cfa344f..04029114ec 100644
--- a/test_runner/regress/test_object_storage.py
+++ b/test_runner/regress/test_endpoint_storage.py
@@ -8,7 +8,7 @@ from jwcrypto import jwk, jwt
 
 
 @pytest.mark.asyncio
-async def test_object_storage_insert_retrieve_delete(neon_simple_env: NeonEnv):
+async def test_endpoint_storage_insert_retrieve_delete(neon_simple_env: NeonEnv):
     """
     Inserts, retrieves, and deletes test file using a JWT token
     """
@@ -31,7 +31,7 @@ async def test_object_storage_insert_retrieve_delete(neon_simple_env: NeonEnv):
     token.make_signed_token(key)
     token = token.serialize()
 
-    base_url = env.object_storage.base_url()
+    base_url = env.endpoint_storage.base_url()
     key = f"http://{base_url}/{tenant_id}/{timeline_id}/{endpoint_id}/key"
     headers = {"Authorization": f"Bearer {token}"}
     log.info(f"cache key url {key}")
diff --git a/test_runner/regress/test_import_pgdata.py b/test_runner/regress/test_import_pgdata.py
index 6b3b71f29c..a26c3994a5 100644
--- a/test_runner/regress/test_import_pgdata.py
+++ b/test_runner/regress/test_import_pgdata.py
@@ -1,9 +1,9 @@
 import base64
 import json
-import re
 import time
 from enum import Enum
 from pathlib import Path
+from threading import Event
 
 import psycopg2
 import psycopg2.errors
@@ -14,12 +14,16 @@ from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnvBuilder, PgBin, PgProtocol, VanillaPostgres
 from fixtures.pageserver.http import (
     ImportPgdataIdemptencyKey,
-    PageserverApiException,
 )
 from fixtures.pg_version import PgVersion
 from fixtures.port_distributor import PortDistributor
 from fixtures.remote_storage import MockS3Server, RemoteStorageKind
-from fixtures.utils import shared_buffers_for_max_cu
+from fixtures.utils import (
+    run_only_on_default_postgres,
+    shared_buffers_for_max_cu,
+    skip_in_debug_build,
+    wait_until,
+)
 from mypy_boto3_kms import KMSClient
 from mypy_boto3_kms.type_defs import EncryptResponseTypeDef
 from mypy_boto3_s3 import S3Client
@@ -44,6 +48,25 @@ smoke_params = [
 ]
 
 
+def mock_import_bucket(vanilla_pg: VanillaPostgres, path: Path):
+    """
+    Mock the import S3 bucket into a local directory for a provided vanilla PG instance.
+    """
+    assert not vanilla_pg.is_running()
+
+    path.mkdir()
+    # what cplane writes before scheduling fast_import
+    specpath = path / "spec.json"
+    specpath.write_text(json.dumps({"branch_id": "somebranch", "project_id": "someproject"}))
+    # what fast_import writes
+    vanilla_pg.pgdatadir.rename(path / "pgdata")
+    statusdir = path / "status"
+    statusdir.mkdir()
+    (statusdir / "pgdata").write_text(json.dumps({"done": True}))
+    (statusdir / "fast_import").write_text(json.dumps({"command": "pgdata", "done": True}))
+
+
+@skip_in_debug_build("MULTIPLE_RELATION_SEGMENTS has non trivial amount of data")
 @pytest.mark.parametrize("shard_count,stripe_size,rel_block_size", smoke_params)
 def test_pgdata_import_smoke(
     vanilla_pg: VanillaPostgres,
@@ -56,24 +79,29 @@ def test_pgdata_import_smoke(
     #
     # Setup fake control plane for import progress
     #
+    import_completion_signaled = Event()
+
     def handler(request: Request) -> Response:
-        log.info(f"control plane request: {request.json}")
+        log.info(f"control plane /import_complete request: {request.json}")
+        import_completion_signaled.set()
         return Response(json.dumps({}), status=200)
 
     cplane_mgmt_api_server = make_httpserver
-    cplane_mgmt_api_server.expect_request(re.compile(".*")).respond_with_handler(handler)
+    cplane_mgmt_api_server.expect_request(
+        "/storage/api/v1/import_complete", method="PUT"
+    ).respond_with_handler(handler)
 
     neon_env_builder.enable_pageserver_remote_storage(RemoteStorageKind.LOCAL_FS)
+
+    neon_env_builder.control_plane_hooks_api = (
+        f"http://{cplane_mgmt_api_server.host}:{cplane_mgmt_api_server.port}/storage/api/v1/"
+    )
+
     env = neon_env_builder.init_start()
 
     # The test needs LocalFs support, which is only built in testing mode.
     env.pageserver.is_testing_enabled_or_skip()
 
-    env.pageserver.patch_config_toml_nonrecursive(
-        {
-            "import_pgdata_upcall_api": f"http://{cplane_mgmt_api_server.host}:{cplane_mgmt_api_server.port}/path/to/mgmt/api"
-        }
-    )
     env.pageserver.stop()
     env.pageserver.start()
 
@@ -150,17 +178,8 @@ def test_pgdata_import_smoke(
     # TODO: actually exercise fast_import here
     # TODO: test s3 remote storage
     #
-    importbucket = neon_env_builder.repo_dir / "importbucket"
-    importbucket.mkdir()
-    # what cplane writes before scheduling fast_import
-    specpath = importbucket / "spec.json"
-    specpath.write_text(json.dumps({"branch_id": "somebranch", "project_id": "someproject"}))
-    # what fast_import writes
-    vanilla_pg.pgdatadir.rename(importbucket / "pgdata")
-    statusdir = importbucket / "status"
-    statusdir.mkdir()
-    (statusdir / "pgdata").write_text(json.dumps({"done": True}))
-    (statusdir / "fast_import").write_text(json.dumps({"command": "pgdata", "done": True}))
+    importbucket_path = neon_env_builder.repo_dir / "importbucket"
+    mock_import_bucket(vanilla_pg, importbucket_path)
 
     #
     # Do the import
@@ -187,46 +206,17 @@ def test_pgdata_import_smoke(
             "new_timeline_id": str(timeline_id),
             "import_pgdata": {
                 "idempotency_key": str(idempotency),
-                "location": {"LocalFs": {"path": str(importbucket.absolute())}},
+                "location": {"LocalFs": {"path": str(importbucket_path.absolute())}},
             },
         },
     )
     env.neon_cli.mappings_map_branch(import_branch_name, tenant_id, timeline_id)
 
-    while True:
-        locations = env.storage_controller.locate(tenant_id)
-        active_count = 0
-        for location in locations:
-            shard_id = TenantShardId.parse(location["shard_id"])
-            ps = env.get_pageserver(location["node_id"])
-            try:
-                detail = ps.http_client().timeline_detail(shard_id, timeline_id)
-                state = detail["state"]
-                log.info(f"shard {shard_id} state: {state}")
-                if state == "Active":
-                    active_count += 1
-            except PageserverApiException as e:
-                if e.status_code == 404:
-                    log.info("not found, import is in progress")
-                    continue
-                elif e.status_code == 429:
-                    log.info("import is in progress")
-                    continue
-                else:
-                    raise
+    def cplane_notified():
+        assert import_completion_signaled.is_set()
 
-            shard_status_file = statusdir / f"shard-{shard_id.shard_index}"
-            if state == "Active":
-                shard_status_file_contents = (
-                    shard_status_file.read_text()
-                )  # Active state implies import is done
-                shard_status = json.loads(shard_status_file_contents)
-                assert shard_status["done"] is True
-
-        if active_count == len(locations):
-            log.info("all shards are active")
-            break
-        time.sleep(1)
+    # Generous timeout for the MULTIPLE_RELATION_SEGMENTS test variants
+    wait_until(cplane_notified, timeout=90)
 
     import_duration = time.monotonic() - start
     log.info(f"import complete; duration={import_duration:.2f}s")
@@ -343,6 +333,87 @@ def test_pgdata_import_smoke(
         br_initdb_endpoint.safe_psql("select * from othertable")
 
 
+@run_only_on_default_postgres(reason="PG version is irrelevant here")
+def test_import_completion_on_restart(
+    neon_env_builder: NeonEnvBuilder, vanilla_pg: VanillaPostgres, make_httpserver: HTTPServer
+):
+    """
+    Validate that the storage controller delivers the import completion notification
+    eventually even if it was restarted when the import initially completed.
+    """
+    # Set up mock control plane HTTP server to listen for import completions
+    import_completion_signaled = Event()
+
+    def handler(request: Request) -> Response:
+        log.info(f"control plane /import_complete request: {request.json}")
+        import_completion_signaled.set()
+        return Response(json.dumps({}), status=200)
+
+    cplane_mgmt_api_server = make_httpserver
+    cplane_mgmt_api_server.expect_request(
+        "/storage/api/v1/import_complete", method="PUT"
+    ).respond_with_handler(handler)
+
+    # Plug the cplane mock in
+    neon_env_builder.control_plane_hooks_api = (
+        f"http://{cplane_mgmt_api_server.host}:{cplane_mgmt_api_server.port}/storage/api/v1/"
+    )
+
+    # The import will specifiy a local filesystem path mocking remote storage
+    neon_env_builder.enable_pageserver_remote_storage(RemoteStorageKind.LOCAL_FS)
+
+    vanilla_pg.start()
+    vanilla_pg.stop()
+
+    env = neon_env_builder.init_configs()
+    env.start()
+
+    importbucket_path = neon_env_builder.repo_dir / "test_import_completion_bucket"
+    mock_import_bucket(vanilla_pg, importbucket_path)
+
+    tenant_id = TenantId.generate()
+    timeline_id = TimelineId.generate()
+    idempotency = ImportPgdataIdemptencyKey.random()
+
+    # Pause before sending the notification
+    failpoint_name = "timeline-import-pre-cplane-notification"
+    env.storage_controller.configure_failpoints((failpoint_name, "pause"))
+
+    env.storage_controller.tenant_create(tenant_id)
+    env.storage_controller.timeline_create(
+        tenant_id,
+        {
+            "new_timeline_id": str(timeline_id),
+            "import_pgdata": {
+                "idempotency_key": str(idempotency),
+                "location": {"LocalFs": {"path": str(importbucket_path.absolute())}},
+            },
+        },
+    )
+
+    def hit_failpoint():
+        log.info("Checking log for pattern...")
+        try:
+            assert env.storage_controller.log_contains(f".*at failpoint {failpoint_name}.*")
+        except Exception:
+            log.exception("Failed to find pattern in log")
+            raise
+
+    wait_until(hit_failpoint)
+    assert not import_completion_signaled.is_set()
+
+    # Restart the storage controller before signalling control plane.
+    # This clears the failpoint and we expect that the import start-up reconciliation
+    # kicks in and notifies cplane.
+    env.storage_controller.stop()
+    env.storage_controller.start()
+
+    def cplane_notified():
+        assert import_completion_signaled.is_set()
+
+    wait_until(cplane_notified)
+
+
 def test_fast_import_with_pageserver_ingest(
     test_output_dir,
     vanilla_pg: VanillaPostgres,
@@ -372,19 +443,27 @@ def test_fast_import_with_pageserver_ingest(
     vanilla_pg.safe_psql("CREATE TABLE foo (a int); INSERT INTO foo SELECT generate_series(1, 10);")
 
     # Setup pageserver and fake cplane for import progress
+    import_completion_signaled = Event()
+
     def handler(request: Request) -> Response:
-        log.info(f"control plane request: {request.json}")
+        log.info(f"control plane /import_complete request: {request.json}")
+        import_completion_signaled.set()
         return Response(json.dumps({}), status=200)
 
     cplane_mgmt_api_server = make_httpserver
-    cplane_mgmt_api_server.expect_request(re.compile(".*")).respond_with_handler(handler)
+    cplane_mgmt_api_server.expect_request(
+        "/storage/api/v1/import_complete", method="PUT"
+    ).respond_with_handler(handler)
+
+    neon_env_builder.control_plane_hooks_api = (
+        f"http://{cplane_mgmt_api_server.host}:{cplane_mgmt_api_server.port}/storage/api/v1/"
+    )
 
     neon_env_builder.enable_pageserver_remote_storage(RemoteStorageKind.MOCK_S3)
     env = neon_env_builder.init_start()
 
     env.pageserver.patch_config_toml_nonrecursive(
         {
-            "import_pgdata_upcall_api": f"http://{cplane_mgmt_api_server.host}:{cplane_mgmt_api_server.port}/path/to/mgmt/api",
             # because import_pgdata code uses this endpoint, not the one in common remote storage config
             # TODO: maybe use common remote_storage config in pageserver?
             "import_pgdata_aws_endpoint_url": env.s3_mock_server.endpoint(),
@@ -476,42 +555,10 @@ def test_fast_import_with_pageserver_ingest(
         conn = PgProtocol(dsn=f"postgresql://cloud_admin@localhost:{pg_port}/neondb")
         validate_vanilla_equivalence(conn)
 
-    # Poll pageserver statuses in s3
-    while True:
-        locations = env.storage_controller.locate(tenant_id)
-        active_count = 0
-        for location in locations:
-            shard_id = TenantShardId.parse(location["shard_id"])
-            ps = env.get_pageserver(location["node_id"])
-            try:
-                detail = ps.http_client().timeline_detail(shard_id, timeline_id)
-                log.info(f"timeline {tenant_id}/{timeline_id} detail: {detail}")
-                state = detail["state"]
-                log.info(f"shard {shard_id} state: {state}")
-                if state == "Active":
-                    active_count += 1
-            except PageserverApiException as e:
-                if e.status_code == 404:
-                    log.info("not found, import is in progress")
-                    continue
-                elif e.status_code == 429:
-                    log.info("import is in progress")
-                    continue
-                else:
-                    raise
+    def cplane_notified():
+        assert import_completion_signaled.is_set()
 
-            if state == "Active":
-                key = f"{key_prefix}/status/shard-{shard_id.shard_index}"
-                shard_status_file_contents = (
-                    mock_s3_client.get_object(Bucket=bucket, Key=key)["Body"].read().decode("utf-8")
-                )
-                shard_status = json.loads(shard_status_file_contents)
-                assert shard_status["done"] is True
-
-        if active_count == len(locations):
-            log.info("all shards are active")
-            break
-        time.sleep(0.5)
+    wait_until(cplane_notified, timeout=60)
 
     import_duration = time.monotonic() - start
     log.info(f"import complete; duration={import_duration:.2f}s")
diff --git a/test_runner/regress/test_neon_cli.py b/test_runner/regress/test_neon_cli.py
index e6bcdf8e67..51a38d9f14 100644
--- a/test_runner/regress/test_neon_cli.py
+++ b/test_runner/regress/test_neon_cli.py
@@ -138,7 +138,7 @@ def test_cli_start_stop(neon_env_builder: NeonEnvBuilder):
     env.neon_cli.pageserver_stop(env.pageserver.id)
     env.neon_cli.safekeeper_stop()
     env.neon_cli.storage_controller_stop(False)
-    env.neon_cli.object_storage_stop(False)
+    env.neon_cli.endpoint_storage_stop(False)
     env.neon_cli.storage_broker_stop()
 
     # Keep NeonEnv state up to date, it usually owns starting/stopping services
@@ -185,7 +185,7 @@ def test_cli_start_stop_multi(neon_env_builder: NeonEnvBuilder):
     env.neon_cli.safekeeper_stop(neon_env_builder.safekeepers_id_start + 1)
     env.neon_cli.safekeeper_stop(neon_env_builder.safekeepers_id_start + 2)
 
-    env.neon_cli.object_storage_stop(False)
+    env.neon_cli.endpoint_storage_stop(False)
 
     # Stop this to get out of the way of the following `start`
     env.neon_cli.storage_controller_stop(False)
diff --git a/test_runner/regress/test_storage_controller.py b/test_runner/regress/test_storage_controller.py
index 0f291030fe..af018f7b5d 100644
--- a/test_runner/regress/test_storage_controller.py
+++ b/test_runner/regress/test_storage_controller.py
@@ -95,7 +95,7 @@ def test_storage_controller_smoke(
     env.pageservers[1].start()
     for sk in env.safekeepers:
         sk.start()
-    env.object_storage.start()
+    env.endpoint_storage.start()
 
     # The pageservers we started should have registered with the sharding service on startup
     nodes = env.storage_controller.node_list()
@@ -347,7 +347,7 @@ def prepare_onboarding_env(
     env = neon_env_builder.init_configs()
     env.broker.start()
     env.storage_controller.start()
-    env.object_storage.start()
+    env.endpoint_storage.start()
 
     # This is the pageserver where we'll initially create the tenant.  Run it in emergency
     # mode so that it doesn't talk to storage controller, and do not register it.
@@ -2894,12 +2894,10 @@ def test_storage_controller_leadership_transfer(
         )
 
 
-@pytest.mark.parametrize("step_down_times_out", [False, True])
 def test_storage_controller_leadership_transfer_during_split(
     neon_env_builder: NeonEnvBuilder,
     storage_controller_proxy: StorageControllerProxy,
     port_distributor: PortDistributor,
-    step_down_times_out: bool,
 ):
     """
     Exercise a race between shard splitting and graceful leadership transfer.  This is
@@ -2940,8 +2938,8 @@ def test_storage_controller_leadership_transfer_during_split(
         )
     env.storage_controller.reconcile_until_idle()
 
-    # We are testing scenarios where the step down API does not complete: either because it is stuck
-    # doing a shard split, or because it totally times out on some other failpoint.
+    # We are testing scenarios where the step down API does not complete: it is stuck
+    # doing a shard split
     env.storage_controller.allowed_errors.extend(
         [
             ".*step_down.*request was dropped before completing.*",
@@ -2949,6 +2947,7 @@ def test_storage_controller_leadership_transfer_during_split(
             ".*Send step down request failed, will retry.*",
             ".*Send step down request still failed after.*retries.*",
             ".*Leader .+ did not respond to step-down request.*",
+            ".*Stopping reconciliations during step down is taking too long.*",
         ]
     )
 
@@ -2960,13 +2959,6 @@ def test_storage_controller_leadership_transfer_during_split(
         pause_failpoint = "shard-split-pre-complete"
         env.storage_controller.configure_failpoints((pause_failpoint, "pause"))
 
-        if not step_down_times_out:
-            # Prevent the timeout self-terminate code from executing: we will block step down on the
-            # shard split itself
-            env.storage_controller.configure_failpoints(
-                ("step-down-delay-timeout", "return(3600000)")
-            )
-
         split_fut = executor.submit(
             env.storage_controller.tenant_shard_split, list(tenants)[0], shard_count * 2
         )
@@ -2985,13 +2977,9 @@ def test_storage_controller_leadership_transfer_during_split(
             timeout_in_seconds=30, instance_id=2, base_port=storage_controller_2_port
         )
 
-        if step_down_times_out:
-            # Step down will time out, original controller will terminate itself
-            env.storage_controller.allowed_errors.extend([".*terminating process.*"])
-        else:
-            # Step down does not time out: original controller hits its shard split completion
-            # code path and realises that it must not purge the parent shards from the database.
-            env.storage_controller.allowed_errors.extend([".*Enqueuing background abort.*"])
+        # Step down does not time out: original controller hits its shard split completion
+        # code path and realises that it must not purge the parent shards from the database.
+        env.storage_controller.allowed_errors.extend([".*Enqueuing background abort.*"])
 
         def passed_split_abort():
             try:
@@ -3007,42 +2995,34 @@ def test_storage_controller_leadership_transfer_during_split(
         wait_until(passed_split_abort, interval=0.1, status_interval=1.0)
         assert env.storage_controller.log_contains(".*Aborting shard split.*")
 
-        if step_down_times_out:
-            # We will let the old controller hit a timeout path where it terminates itself, rather than
-            # completing step_down and trying to complete a shard split
-            def old_controller_terminated():
-                assert env.storage_controller.log_contains(".*terminating process.*")
+        # Proxy is still talking to original controller here: disable its pause failpoint so
+        # that its shard split can run to completion.
+        log.info("Disabling failpoint")
+        # Bypass the proxy: the python test HTTPServer is single threaded and still blocked
+        # on handling the shard split request.
+        env.storage_controller.request(
+            "PUT",
+            f"http://127.0.0.1:{storage_controller_1_port}/debug/v1/failpoints",
+            json=[{"name": "shard-split-pre-complete", "actions": "off"}],
+            headers=env.storage_controller.headers(TokenScope.ADMIN),
+        )
 
-            wait_until(old_controller_terminated)
-        else:
-            # Proxy is still talking to original controller here: disable its pause failpoint so
-            # that its shard split can run to completion.
-            log.info("Disabling failpoint")
-            # Bypass the proxy: the python test HTTPServer is single threaded and still blocked
-            # on handling the shard split request.
-            env.storage_controller.request(
-                "PUT",
-                f"http://127.0.0.1:{storage_controller_1_port}/debug/v1/failpoints",
-                json=[{"name": "shard-split-pre-complete", "actions": "off"}],
-                headers=env.storage_controller.headers(TokenScope.ADMIN),
+        def previous_stepped_down():
+            assert (
+                env.storage_controller.get_leadership_status()
+                == StorageControllerLeadershipStatus.STEPPED_DOWN
             )
 
-            def previous_stepped_down():
-                assert (
-                    env.storage_controller.get_leadership_status()
-                    == StorageControllerLeadershipStatus.STEPPED_DOWN
-                )
+        log.info("Awaiting step down")
+        wait_until(previous_stepped_down)
 
-            log.info("Awaiting step down")
-            wait_until(previous_stepped_down)
-
-            # Let the shard split complete: this may happen _after_ the replacement has come up
-            # and tried to clean up the databases
-            log.info("Unblocking & awaiting shard split")
-            with pytest.raises(Exception, match="Unexpected child shard count"):
-                # This split fails when it tries to persist results, because it encounters
-                # changes already made by the new controller's abort-on-startup
-                split_fut.result()
+        # Let the shard split complete: this may happen _after_ the replacement has come up
+        # and tried to clean up the databases
+        log.info("Unblocking & awaiting shard split")
+        with pytest.raises(Exception, match="Unexpected child shard count"):
+            # This split fails when it tries to persist results, because it encounters
+            # changes already made by the new controller's abort-on-startup
+            split_fut.result()
 
         log.info("Routing to new leader")
         storage_controller_proxy.route_to(f"http://127.0.0.1:{storage_controller_2_port}")
@@ -3060,14 +3040,13 @@ def test_storage_controller_leadership_transfer_during_split(
     env.storage_controller.wait_until_ready()
     env.storage_controller.consistency_check()
 
-    if not step_down_times_out:
-        # Check that the stepped down instance forwards requests
-        # to the new leader while it's still running.
-        storage_controller_proxy.route_to(f"http://127.0.0.1:{storage_controller_1_port}")
-        env.storage_controller.tenant_shard_dump()
-        env.storage_controller.node_configure(env.pageservers[0].id, {"scheduling": "Pause"})
-        status = env.storage_controller.node_status(env.pageservers[0].id)
-        assert status["scheduling"] == "Pause"
+    # Check that the stepped down instance forwards requests
+    # to the new leader while it's still running.
+    storage_controller_proxy.route_to(f"http://127.0.0.1:{storage_controller_1_port}")
+    env.storage_controller.tenant_shard_dump()
+    env.storage_controller.node_configure(env.pageservers[0].id, {"scheduling": "Pause"})
+    status = env.storage_controller.node_status(env.pageservers[0].id)
+    assert status["scheduling"] == "Pause"
 
 
 def test_storage_controller_ps_restarted_during_drain(neon_env_builder: NeonEnvBuilder):
diff --git a/workspace_hack/Cargo.toml b/workspace_hack/Cargo.toml
index b548a2a88a..f3d8b951a8 100644
--- a/workspace_hack/Cargo.toml
+++ b/workspace_hack/Cargo.toml
@@ -77,6 +77,8 @@ regex-automata = { version = "0.4", default-features = false, features = ["dfa-o
 regex-syntax = { version = "0.8" }
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "json", "rustls-tls", "rustls-tls-native-roots", "stream"] }
 rustls = { version = "0.23", default-features = false, features = ["logging", "ring", "std", "tls12"] }
+rustls-pki-types = { version = "1", features = ["std"] }
+rustls-webpki = { version = "0.102", default-features = false, features = ["ring", "std"] }
 scopeguard = { version = "1" }
 sec1 = { version = "0.7", features = ["pem", "serde", "std", "subtle"] }
 serde = { version = "1", features = ["alloc", "derive"] }
@@ -103,7 +105,6 @@ tracing-core = { version = "0.1" }
 tracing-log = { version = "0.2" }
 url = { version = "2", features = ["serde"] }
 uuid = { version = "1", features = ["serde", "v4", "v7"] }
-zerocopy = { version = "0.7", features = ["derive", "simd"] }
 zeroize = { version = "1", features = ["derive", "serde"] }
 zstd = { version = "0.13" }
 zstd-safe = { version = "7", default-features = false, features = ["arrays", "legacy", "std", "zdict_builder"] }
@@ -146,7 +147,6 @@ serde = { version = "1", features = ["alloc", "derive"] }
 syn = { version = "2", features = ["extra-traits", "fold", "full", "visit", "visit-mut"] }
 time-macros = { version = "0.2", default-features = false, features = ["formatting", "parsing", "serde"] }
 toml_edit = { version = "0.22", features = ["serde"] }
-zerocopy = { version = "0.7", features = ["derive", "simd"] }
 zstd = { version = "0.13" }
 zstd-safe = { version = "7", default-features = false, features = ["arrays", "legacy", "std", "zdict_builder"] }
 zstd-sys = { version = "2", default-features = false, features = ["legacy", "std", "zdict_builder"] }