From 8d479d1f2bc0e385fd72b14b18de442cd17e3d8c Mon Sep 17 00:00:00 2001
From: Cam Quilici <cjquilici@gmail.com>
Date: Tue, 8 Sep 2026 14:35:21 -0500
Subject: [PATCH 1/3] fix(runners): import B300 images on the login host
 [skip-sweep]

---
 docs/configuration-procedures.md    |  15 ++++
 docs/configuration-procedures_zh.md |  14 ++++
 runners/launch_b300-dsxe.sh         |  62 ++++++++------
 utils/test_b300_image_import.py     | 126 ++++++++++++++++++++++++++++
 4 files changed, 192 insertions(+), 25 deletions(-)
 create mode 100644 utils/test_b300_image_import.py

diff --git a/docs/configuration-procedures.md b/docs/configuration-procedures.md
index e42027abb5..60b8d9054e 100644
--- a/docs/configuration-procedures.md
+++ b/docs/configuration-procedures.md
@@ -112,6 +112,21 @@ The runner-name prefix is load-bearing: workflow routing uses `launch_${RUNNER_N
 6. Verify every runner is **Idle** in [repository runner settings](https://github.com/SemiAnalysisAI/InferenceX/settings/actions/runners) before adding it to sweep traffic.
 7. Verify launcher mounts for `_work`, HF cache, staged weights, and squash images from a compute node. Root containers must not leave root-owned files in the shared workspace.
 
+### B300 DSXE image imports
+
+`launch_b300-dsxe.sh` downloads and converts images on the runner/login host,
+before requesting benchmark nodes. Cold imports share a lock to limit login-host
+resource use; validated images are published atomically in the shared squash
+directory. Enroot defaults to two processors and two download connections.
+
+Unpacking uses a private directory under `ENROOT_TEMP_PATH` (default `/tmp`).
+This must be a local filesystem with enough space for the unpacked image layers,
+not Lustre. Set it to a larger local scratch volume when needed. The downloaded
+layer cache defaults to `.enroot-cache` in the shared squash directory;
+`ENROOT_CACHE_PATH` can override it. `ENROOT_IMPORT_TIME_LIMIT` bounds each import
+in minutes (default 120). Compute nodes still need healthy shared-storage access
+to read the completed image and benchmark workspace.
+
 ## Register an srt-slurm recipe
 
 Mapping source: [`benchmarks/multi_node/srt-slurm-recipes/RECIPES.md`](../benchmarks/multi_node/srt-slurm-recipes/RECIPES.md). Checked-in recipes: [`benchmarks/multi_node/srt-slurm-recipes/`](../benchmarks/multi_node/srt-slurm-recipes/).
diff --git a/docs/configuration-procedures_zh.md b/docs/configuration-procedures_zh.md
index 0ebd17fc68..b41ae9ed1a 100644
--- a/docs/configuration-procedures_zh.md
+++ b/docs/configuration-procedures_zh.md
@@ -112,6 +112,20 @@ runner 名称前缀是关键契约：workflow 通过 `launch_${RUNNER_NAME%%_*}.
 6. 将 runner 加入 sweep 流量前，在[仓库 runner 设置页](https://github.com/SemiAnalysisAI/InferenceX/settings/actions/runners)确认每个 runner 都是 **Idle**。
 7. 从计算节点验证 launcher 对 `_work`、HF cache、预置权重和 squash 镜像的挂载。root 容器不得在共享 workspace 留下 root 所有的文件。
 
+### B300 DSXE 镜像导入
+
+`launch_b300-dsxe.sh` 在申请基准测试节点之前，先在运行器所在的登录主机上
+下载并转换镜像。未缓存镜像的导入共用一把锁，以限制登录主机的资源占用；
+镜像通过验证后，才原子发布到共享 squash 目录。Enroot 默认使用两个处理器
+和两个下载连接。
+
+解包使用 `ENROOT_TEMP_PATH`（默认 `/tmp`）下的独立临时目录。该路径必须位于
+本地文件系统，且有足够空间容纳解包后的镜像层，不能使用 Lustre；空间不足时，
+应将其指向更大的本地临时存储卷。下载层缓存默认保存在共享 squash 目录下的
+`.enroot-cache`，可通过 `ENROOT_CACHE_PATH` 覆盖。`ENROOT_IMPORT_TIME_LIMIT`
+以分钟为单位限制单次导入时长（默认 120）。计算节点仍然需要正常的共享存储
+连接，才能读取完成的镜像和基准测试工作区。
+
 ## 注册 srt-slurm 配方
 
 映射来源：[`benchmarks/multi_node/srt-slurm-recipes/RECIPES.md`](../benchmarks/multi_node/srt-slurm-recipes/RECIPES.md)。检入的配方：[`benchmarks/multi_node/srt-slurm-recipes/`](../benchmarks/multi_node/srt-slurm-recipes/)。
diff --git a/runners/launch_b300-dsxe.sh b/runners/launch_b300-dsxe.sh
index c229146bfa..93dccc6a4d 100755
--- a/runners/launch_b300-dsxe.sh
+++ b/runners/launch_b300-dsxe.sh
@@ -74,39 +74,51 @@ set -x
 # when execution reaches it, so moving this inside either branch silently removes
 # it from the other and the job dies on "command not found" at import time.
 #
-# Import a container image into the shared squash dir. Concurrent callers target the
-# same path, so serialize on a per-file lock and skip when a valid squash file exists.
-# --time bounds the step; an unbounded srun hangs the job if its step is lost.
-#
-# The import itself must run on a compute node: enroot builds the squashfs over an
-# overlay mount, which the shared filesystem cannot back, and the login host is too
-# small to unpack a multi-GB image. Reading the finished file is just I/O, so probe
-# it here first -- a warm cache then costs no Slurm allocation at all. The in-srun
-# check under the lock stays authoritative, so a stale probe only costs one step.
+# Import on the runner/login host; shared storage holds the layer cache and images.
+# Enroot's extracted layers and overlay mount must use node-local scratch.
+# Serialize cold imports across images to bound login-host CPU and disk usage.
 import_squash_image() {
     local image_ref="$1"
     local sqsh="$2"
-    local lock="${2}.lock"
 
     if unsquashfs -l "$sqsh" > /dev/null 2>&1; then
         echo "Squash file already present, skipping import: $sqsh"
         return 0
     fi
 
-    srun -N 1 -A "$SLURM_ACCOUNT" -p "$SLURM_PARTITION" \
-        --time="${ENROOT_IMPORT_TIME_LIMIT:-120}" bash -c "
-        set -euo pipefail
-        exec 9>\"$lock\"
-        flock -w 3600 9
-        if unsquashfs -l \"$sqsh\" > /dev/null 2>&1; then
+    (
+        set -uo pipefail
+        exec 9>"$SQUASH_DIR/.import.lock" || exit 1
+        flock -w 7200 9 || { echo "Timed out waiting for the image import lock" >&2; exit 1; }
+        # Keep the per-image lock compatible with runners on the old launcher.
+        exec 8>"${sqsh}.lock" || exit 1
+        flock -w 7200 8 || { echo "Timed out waiting for $sqsh" >&2; exit 1; }
+        # Another runner may have populated this image while we waited.
+        if unsquashfs -l "$sqsh" > /dev/null 2>&1; then
+            echo "Squash file already present, skipping import: $sqsh"
             exit 0
         fi
-        rm -f \"$sqsh\"
-        enroot import -o \"$sqsh\" \"docker://$image_ref\"
-        unsquashfs -l \"$sqsh\" > /dev/null
-    " || { echo "Error: enroot import failed for $image_ref -> $sqsh" >&2; exit 1; }
 
-    test -r "$sqsh" || { echo "Error: squash file not readable: $sqsh" >&2; exit 1; }
+        local work_dir partial
+        work_dir=$(mktemp -d "${ENROOT_TEMP_PATH:-/tmp}/inferencex-enroot.XXXXXX") || exit 1
+        partial="${sqsh}.tmp.${work_dir##*/}"
+        trap 'rm -f -- "$partial"; rm -rf -- "$work_dir"' EXIT
+        trap 'exit 143' TERM
+        trap 'exit 130' INT
+        export ENROOT_TEMP_PATH="$work_dir"
+        export ENROOT_RUNTIME_PATH="$work_dir/runtime"
+        export ENROOT_DATA_PATH="$work_dir/data"
+        export ENROOT_CACHE_PATH="${ENROOT_CACHE_PATH:-$SQUASH_DIR/.enroot-cache}"
+        export ENROOT_MAX_PROCESSORS="${ENROOT_MAX_PROCESSORS:-2}"
+        export ENROOT_MAX_CONNECTIONS="${ENROOT_MAX_CONNECTIONS:-2}"
+
+        echo "Importing $image_ref on $(hostname) using local scratch $work_dir"
+        timeout --kill-after=30 "${ENROOT_IMPORT_TIME_LIMIT:-120}m" \
+            enroot import -o "$partial" "docker://$image_ref" || exit 1
+        unsquashfs -l "$partial" > /dev/null || exit 1
+        # Publish only a validated image, without exposing partial imports.
+        mv -f -- "$partial" "$sqsh" || exit 1
+    ) || { echo "Error: enroot import failed for $image_ref -> $sqsh" >&2; return 1; }
 }
 
 if [[ "$IS_MULTINODE" == "true" ]]; then
@@ -202,15 +214,15 @@ SQUASH_FILE="$SQUASH_DIR/$(echo "$IMAGE" | sed 's/[\/:@#]/_/g').sqsh"
 NGINX_SQUASH_FILE="$SQUASH_DIR/$(echo "$NGINX_IMAGE" | sed 's/[\/:@#]/_/g').sqsh"
 
 # Import containers via enroot
-import_squash_image "$IMAGE" "$SQUASH_FILE"
-import_squash_image "$NGINX_IMAGE" "$NGINX_SQUASH_FILE"
+import_squash_image "$IMAGE" "$SQUASH_FILE" || exit 1
+import_squash_image "$NGINX_IMAGE" "$NGINX_SQUASH_FILE" || exit 1
 
 if [[ "$USES_DCGM_POWER" == "1" ]]; then
     DCGM_EXPORTER_IMAGE="nvcr.io/nvidia/k8s/dcgm-exporter:4.6.0-4.8.3-distroless"
     # enroot resolves bare paths against Docker Hub; nvcr.io pulls need the registry# form
     DCGM_EXPORTER_ENROOT_REF="${DCGM_EXPORTER_IMAGE/nvcr.io\//nvcr.io#}"
     DCGM_EXPORTER_SQSH="$SQUASH_DIR/$(echo "$DCGM_EXPORTER_IMAGE" | sed 's/[\/:@#]/_/g').sqsh"
-    import_squash_image "$DCGM_EXPORTER_ENROOT_REF" "$DCGM_EXPORTER_SQSH"
+    import_squash_image "$DCGM_EXPORTER_ENROOT_REF" "$DCGM_EXPORTER_SQSH" || exit 1
     sha256sum "$DCGM_EXPORTER_SQSH" > "$GITHUB_WORKSPACE/exporter-image.sha256"
 fi
 
@@ -474,7 +486,7 @@ else
         CONTAINER_MOUNT_DIR=/workspace
     fi
 
-    import_squash_image "$IMAGE" "$SQUASH_FILE"
+    import_squash_image "$IMAGE" "$SQUASH_FILE" || exit 1
 
     export GPU_COUNT="${GPU_COUNT:-${TP:?TP must be set}}"
 
diff --git a/utils/test_b300_image_import.py b/utils/test_b300_image_import.py
new file mode 100644
index 0000000000..88889a0953
--- /dev/null
+++ b/utils/test_b300_image_import.py
@@ -0,0 +1,126 @@
+"""Exercise the launcher's local import, cache publication, and failure paths."""
+
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def write_executable(path: Path, source: str, *, python: bool = False) -> None:
+    path.write_text(f"#!{sys.executable if python else '/bin/bash'}\n" + source)
+    path.chmod(0o755)
+
+
+@pytest.fixture
+def importer(tmp_path: Path) -> tuple[Path, dict[str, str], Path]:
+    bin_dir = tmp_path / "bin"
+    bin_dir.mkdir()
+    squash_dir = tmp_path / "squash"
+    squash_dir.mkdir()
+    scratch = tmp_path / "scratch"
+    scratch.mkdir()
+    # macOS has no util-linux flock or GNU timeout. Keep real advisory locking
+    # through fcntl; the cluster smoke uses the actual Linux commands.
+    write_executable(
+        bin_dir / "flock",
+        "import fcntl, sys\nfcntl.flock(int(sys.argv[-1]), fcntl.LOCK_EX)\n",
+        python=True,
+    )
+    write_executable(bin_dir / "timeout", 'shift 2\nexec "$@"\n')
+    write_executable(bin_dir / "srun", 'echo "unexpected Slurm allocation" >&2\nexit 99\n')
+    write_executable(
+        bin_dir / "unsquashfs",
+        "import pathlib, sys\np = pathlib.Path(sys.argv[2])\n"
+        "sys.exit(0 if p.exists() and p.read_bytes() == b'valid' else 1)\n",
+        python=True,
+    )
+    write_executable(
+        bin_dir / "enroot",
+        """import os, pathlib, sys, time
+active = pathlib.Path(os.environ['IMPORT_LOG'] + '.active')
+active.mkdir()  # Concurrent cold imports must not overlap on the login host.
+try:
+    with open(os.environ['IMPORT_LOG'], 'a') as log:
+        log.write(os.environ['ENROOT_TEMP_PATH'] + '\\n')
+    p = pathlib.Path(sys.argv[3])
+    p.write_bytes(b'partial')
+    time.sleep(0.2)
+    mode = os.environ.get('IMPORT_MODE', 'success')
+    if mode == 'failure':
+        sys.exit(42)
+    if mode != 'invalid':
+        p.write_bytes(b'valid')
+finally:
+    active.rmdir()
+""",
+        python=True,
+    )
+    source = (ROOT / "runners/launch_b300-dsxe.sh").read_text()
+    start = source.index("import_squash_image() {")
+    end = source.index('\nif [[ "$IS_MULTINODE"', start)
+    harness = tmp_path / "import.sh"
+    harness.write_text(
+        source[start:end] + '\nimport_squash_image example/test:tag "$1" || exit 1\n'
+    )
+    env = {
+        **os.environ,
+        "PATH": f"{bin_dir}:{os.environ['PATH']}",
+        "SQUASH_DIR": str(squash_dir),
+        "ENROOT_TEMP_PATH": str(scratch),
+        "IMPORT_LOG": str(tmp_path / "imports.log"),
+    }
+    return harness, env, squash_dir / "image.sqsh"
+
+
+def run_import(importer: tuple[Path, dict[str, str], Path]) -> subprocess.CompletedProcess:
+    harness, env, squash = importer
+    return subprocess.run(
+        ["bash", str(harness), str(squash)], env=env,
+        capture_output=True, text=True, timeout=10,
+    )
+
+
+def test_warm_image_needs_no_import(importer) -> None:
+    _, env, squash = importer
+    squash.write_bytes(b"valid")
+    assert run_import(importer).returncode == 0
+    assert not Path(env["IMPORT_LOG"]).exists()
+
+
+@pytest.mark.parametrize("distinct_images", [False, True])
+def test_concurrent_callers_serialize_and_clean_local_scratch(importer, distinct_images: bool) -> None:
+    harness, env, squash = importer
+    targets = [squash, squash.with_name("second.sqsh") if distinct_images else squash]
+    processes = [
+        subprocess.Popen(
+            ["bash", str(harness), str(target)], env=env,
+            stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True,
+        )
+        for target in targets
+    ]
+    for process in processes:
+        _, stderr = process.communicate(timeout=10)
+        assert process.returncode == 0, stderr
+    assert all(target.read_bytes() == b"valid" for target in targets)
+    imports = Path(env["IMPORT_LOG"]).read_text().splitlines()
+    assert len(imports) == (2 if distinct_images else 1)
+    for path in imports:
+        assert Path(path).parent == Path(env["ENROOT_TEMP_PATH"])
+        assert not Path(path).exists()
+    assert not list(squash.parent.glob("*.tmp.*"))
+
+
+@pytest.mark.parametrize("mode", ["failure", "invalid"])
+def test_failed_import_never_publishes_partial_image(importer, mode: str) -> None:
+    _, env, squash = importer
+    env["IMPORT_MODE"] = mode
+    squash.write_bytes(b"previous-invalid-image")
+    result = run_import(importer)
+    assert result.returncode != 0
+    assert squash.read_bytes() == b"previous-invalid-image"
+    assert not list(squash.parent.glob("*.tmp.*"))
+    assert not list(Path(env["ENROOT_TEMP_PATH"]).iterdir())

From 96773232f48df0d9e311ca54e4dc4e7771f9ed7f Mon Sep 17 00:00:00 2001
From: Cam Quilici <cjquilici@gmail.com>
Date: Tue, 8 Sep 2026 14:37:24 -0500
Subject: [PATCH 2/3] test: remove B300 image import tests [skip-sweep]

---
 utils/test_b300_image_import.py | 126 --------------------------------
 1 file changed, 126 deletions(-)
 delete mode 100644 utils/test_b300_image_import.py

diff --git a/utils/test_b300_image_import.py b/utils/test_b300_image_import.py
deleted file mode 100644
index 88889a0953..0000000000
--- a/utils/test_b300_image_import.py
+++ /dev/null
@@ -1,126 +0,0 @@
-"""Exercise the launcher's local import, cache publication, and failure paths."""
-
-import os
-import subprocess
-import sys
-from pathlib import Path
-
-import pytest
-
-ROOT = Path(__file__).resolve().parents[1]
-
-
-def write_executable(path: Path, source: str, *, python: bool = False) -> None:
-    path.write_text(f"#!{sys.executable if python else '/bin/bash'}\n" + source)
-    path.chmod(0o755)
-
-
-@pytest.fixture
-def importer(tmp_path: Path) -> tuple[Path, dict[str, str], Path]:
-    bin_dir = tmp_path / "bin"
-    bin_dir.mkdir()
-    squash_dir = tmp_path / "squash"
-    squash_dir.mkdir()
-    scratch = tmp_path / "scratch"
-    scratch.mkdir()
-    # macOS has no util-linux flock or GNU timeout. Keep real advisory locking
-    # through fcntl; the cluster smoke uses the actual Linux commands.
-    write_executable(
-        bin_dir / "flock",
-        "import fcntl, sys\nfcntl.flock(int(sys.argv[-1]), fcntl.LOCK_EX)\n",
-        python=True,
-    )
-    write_executable(bin_dir / "timeout", 'shift 2\nexec "$@"\n')
-    write_executable(bin_dir / "srun", 'echo "unexpected Slurm allocation" >&2\nexit 99\n')
-    write_executable(
-        bin_dir / "unsquashfs",
-        "import pathlib, sys\np = pathlib.Path(sys.argv[2])\n"
-        "sys.exit(0 if p.exists() and p.read_bytes() == b'valid' else 1)\n",
-        python=True,
-    )
-    write_executable(
-        bin_dir / "enroot",
-        """import os, pathlib, sys, time
-active = pathlib.Path(os.environ['IMPORT_LOG'] + '.active')
-active.mkdir()  # Concurrent cold imports must not overlap on the login host.
-try:
-    with open(os.environ['IMPORT_LOG'], 'a') as log:
-        log.write(os.environ['ENROOT_TEMP_PATH'] + '\\n')
-    p = pathlib.Path(sys.argv[3])
-    p.write_bytes(b'partial')
-    time.sleep(0.2)
-    mode = os.environ.get('IMPORT_MODE', 'success')
-    if mode == 'failure':
-        sys.exit(42)
-    if mode != 'invalid':
-        p.write_bytes(b'valid')
-finally:
-    active.rmdir()
-""",
-        python=True,
-    )
-    source = (ROOT / "runners/launch_b300-dsxe.sh").read_text()
-    start = source.index("import_squash_image() {")
-    end = source.index('\nif [[ "$IS_MULTINODE"', start)
-    harness = tmp_path / "import.sh"
-    harness.write_text(
-        source[start:end] + '\nimport_squash_image example/test:tag "$1" || exit 1\n'
-    )
-    env = {
-        **os.environ,
-        "PATH": f"{bin_dir}:{os.environ['PATH']}",
-        "SQUASH_DIR": str(squash_dir),
-        "ENROOT_TEMP_PATH": str(scratch),
-        "IMPORT_LOG": str(tmp_path / "imports.log"),
-    }
-    return harness, env, squash_dir / "image.sqsh"
-
-
-def run_import(importer: tuple[Path, dict[str, str], Path]) -> subprocess.CompletedProcess:
-    harness, env, squash = importer
-    return subprocess.run(
-        ["bash", str(harness), str(squash)], env=env,
-        capture_output=True, text=True, timeout=10,
-    )
-
-
-def test_warm_image_needs_no_import(importer) -> None:
-    _, env, squash = importer
-    squash.write_bytes(b"valid")
-    assert run_import(importer).returncode == 0
-    assert not Path(env["IMPORT_LOG"]).exists()
-
-
-@pytest.mark.parametrize("distinct_images", [False, True])
-def test_concurrent_callers_serialize_and_clean_local_scratch(importer, distinct_images: bool) -> None:
-    harness, env, squash = importer
-    targets = [squash, squash.with_name("second.sqsh") if distinct_images else squash]
-    processes = [
-        subprocess.Popen(
-            ["bash", str(harness), str(target)], env=env,
-            stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True,
-        )
-        for target in targets
-    ]
-    for process in processes:
-        _, stderr = process.communicate(timeout=10)
-        assert process.returncode == 0, stderr
-    assert all(target.read_bytes() == b"valid" for target in targets)
-    imports = Path(env["IMPORT_LOG"]).read_text().splitlines()
-    assert len(imports) == (2 if distinct_images else 1)
-    for path in imports:
-        assert Path(path).parent == Path(env["ENROOT_TEMP_PATH"])
-        assert not Path(path).exists()
-    assert not list(squash.parent.glob("*.tmp.*"))
-
-
-@pytest.mark.parametrize("mode", ["failure", "invalid"])
-def test_failed_import_never_publishes_partial_image(importer, mode: str) -> None:
-    _, env, squash = importer
-    env["IMPORT_MODE"] = mode
-    squash.write_bytes(b"previous-invalid-image")
-    result = run_import(importer)
-    assert result.returncode != 0
-    assert squash.read_bytes() == b"previous-invalid-image"
-    assert not list(squash.parent.glob("*.tmp.*"))
-    assert not list(Path(env["ENROOT_TEMP_PATH"]).iterdir())

From fffdaa162944cfac85bbbcaa820ac9a090acec50 Mon Sep 17 00:00:00 2001
From: Cam Quilici <cjquilici@gmail.com>
Date: Tue, 8 Sep 2026 14:38:30 -0500
Subject: [PATCH 3/3] fix(runners): simplify B300 import to a local call
 [skip-sweep]

---
 docs/configuration-procedures.md    | 15 --------
 docs/configuration-procedures_zh.md | 14 --------
 runners/launch_b300-dsxe.sh         | 55 ++++++++++-------------------
 3 files changed, 18 insertions(+), 66 deletions(-)

diff --git a/docs/configuration-procedures.md b/docs/configuration-procedures.md
index 60b8d9054e..e42027abb5 100644
--- a/docs/configuration-procedures.md
+++ b/docs/configuration-procedures.md
@@ -112,21 +112,6 @@ The runner-name prefix is load-bearing: workflow routing uses `launch_${RUNNER_N
 6. Verify every runner is **Idle** in [repository runner settings](https://github.com/SemiAnalysisAI/InferenceX/settings/actions/runners) before adding it to sweep traffic.
 7. Verify launcher mounts for `_work`, HF cache, staged weights, and squash images from a compute node. Root containers must not leave root-owned files in the shared workspace.
 
-### B300 DSXE image imports
-
-`launch_b300-dsxe.sh` downloads and converts images on the runner/login host,
-before requesting benchmark nodes. Cold imports share a lock to limit login-host
-resource use; validated images are published atomically in the shared squash
-directory. Enroot defaults to two processors and two download connections.
-
-Unpacking uses a private directory under `ENROOT_TEMP_PATH` (default `/tmp`).
-This must be a local filesystem with enough space for the unpacked image layers,
-not Lustre. Set it to a larger local scratch volume when needed. The downloaded
-layer cache defaults to `.enroot-cache` in the shared squash directory;
-`ENROOT_CACHE_PATH` can override it. `ENROOT_IMPORT_TIME_LIMIT` bounds each import
-in minutes (default 120). Compute nodes still need healthy shared-storage access
-to read the completed image and benchmark workspace.
-
 ## Register an srt-slurm recipe
 
 Mapping source: [`benchmarks/multi_node/srt-slurm-recipes/RECIPES.md`](../benchmarks/multi_node/srt-slurm-recipes/RECIPES.md). Checked-in recipes: [`benchmarks/multi_node/srt-slurm-recipes/`](../benchmarks/multi_node/srt-slurm-recipes/).
diff --git a/docs/configuration-procedures_zh.md b/docs/configuration-procedures_zh.md
index b41ae9ed1a..0ebd17fc68 100644
--- a/docs/configuration-procedures_zh.md
+++ b/docs/configuration-procedures_zh.md
@@ -112,20 +112,6 @@ runner 名称前缀是关键契约：workflow 通过 `launch_${RUNNER_NAME%%_*}.
 6. 将 runner 加入 sweep 流量前，在[仓库 runner 设置页](https://github.com/SemiAnalysisAI/InferenceX/settings/actions/runners)确认每个 runner 都是 **Idle**。
 7. 从计算节点验证 launcher 对 `_work`、HF cache、预置权重和 squash 镜像的挂载。root 容器不得在共享 workspace 留下 root 所有的文件。
 
-### B300 DSXE 镜像导入
-
-`launch_b300-dsxe.sh` 在申请基准测试节点之前，先在运行器所在的登录主机上
-下载并转换镜像。未缓存镜像的导入共用一把锁，以限制登录主机的资源占用；
-镜像通过验证后，才原子发布到共享 squash 目录。Enroot 默认使用两个处理器
-和两个下载连接。
-
-解包使用 `ENROOT_TEMP_PATH`（默认 `/tmp`）下的独立临时目录。该路径必须位于
-本地文件系统，且有足够空间容纳解包后的镜像层，不能使用 Lustre；空间不足时，
-应将其指向更大的本地临时存储卷。下载层缓存默认保存在共享 squash 目录下的
-`.enroot-cache`，可通过 `ENROOT_CACHE_PATH` 覆盖。`ENROOT_IMPORT_TIME_LIMIT`
-以分钟为单位限制单次导入时长（默认 120）。计算节点仍然需要正常的共享存储
-连接，才能读取完成的镜像和基准测试工作区。
-
 ## 注册 srt-slurm 配方
 
 映射来源：[`benchmarks/multi_node/srt-slurm-recipes/RECIPES.md`](../benchmarks/multi_node/srt-slurm-recipes/RECIPES.md)。检入的配方：[`benchmarks/multi_node/srt-slurm-recipes/`](../benchmarks/multi_node/srt-slurm-recipes/)。
diff --git a/runners/launch_b300-dsxe.sh b/runners/launch_b300-dsxe.sh
index 93dccc6a4d..6ff9c2dfa3 100755
--- a/runners/launch_b300-dsxe.sh
+++ b/runners/launch_b300-dsxe.sh
@@ -74,51 +74,32 @@ set -x
 # when execution reaches it, so moving this inside either branch silently removes
 # it from the other and the job dies on "command not found" at import time.
 #
-# Import on the runner/login host; shared storage holds the layer cache and images.
-# Enroot's extracted layers and overlay mount must use node-local scratch.
-# Serialize cold imports across images to bound login-host CPU and disk usage.
+# Import a container image into the shared squash dir. Concurrent callers target the
+# same path, so serialize on a per-file lock and skip when a valid squash file exists.
+# Run the import locally on the runner/login host using its Enroot configuration.
 import_squash_image() {
     local image_ref="$1"
     local sqsh="$2"
+    local lock="${2}.lock"
 
     if unsquashfs -l "$sqsh" > /dev/null 2>&1; then
         echo "Squash file already present, skipping import: $sqsh"
         return 0
     fi
 
-    (
-        set -uo pipefail
-        exec 9>"$SQUASH_DIR/.import.lock" || exit 1
-        flock -w 7200 9 || { echo "Timed out waiting for the image import lock" >&2; exit 1; }
-        # Keep the per-image lock compatible with runners on the old launcher.
-        exec 8>"${sqsh}.lock" || exit 1
-        flock -w 7200 8 || { echo "Timed out waiting for $sqsh" >&2; exit 1; }
-        # Another runner may have populated this image while we waited.
-        if unsquashfs -l "$sqsh" > /dev/null 2>&1; then
-            echo "Squash file already present, skipping import: $sqsh"
+    bash -c "
+        set -euo pipefail
+        exec 9>\"$lock\"
+        flock -w 3600 9
+        if unsquashfs -l \"$sqsh\" > /dev/null 2>&1; then
             exit 0
         fi
+        rm -f \"$sqsh\"
+        enroot import -o \"$sqsh\" \"docker://$image_ref\"
+        unsquashfs -l \"$sqsh\" > /dev/null
+    " || { echo "Error: enroot import failed for $image_ref -> $sqsh" >&2; exit 1; }
 
-        local work_dir partial
-        work_dir=$(mktemp -d "${ENROOT_TEMP_PATH:-/tmp}/inferencex-enroot.XXXXXX") || exit 1
-        partial="${sqsh}.tmp.${work_dir##*/}"
-        trap 'rm -f -- "$partial"; rm -rf -- "$work_dir"' EXIT
-        trap 'exit 143' TERM
-        trap 'exit 130' INT
-        export ENROOT_TEMP_PATH="$work_dir"
-        export ENROOT_RUNTIME_PATH="$work_dir/runtime"
-        export ENROOT_DATA_PATH="$work_dir/data"
-        export ENROOT_CACHE_PATH="${ENROOT_CACHE_PATH:-$SQUASH_DIR/.enroot-cache}"
-        export ENROOT_MAX_PROCESSORS="${ENROOT_MAX_PROCESSORS:-2}"
-        export ENROOT_MAX_CONNECTIONS="${ENROOT_MAX_CONNECTIONS:-2}"
-
-        echo "Importing $image_ref on $(hostname) using local scratch $work_dir"
-        timeout --kill-after=30 "${ENROOT_IMPORT_TIME_LIMIT:-120}m" \
-            enroot import -o "$partial" "docker://$image_ref" || exit 1
-        unsquashfs -l "$partial" > /dev/null || exit 1
-        # Publish only a validated image, without exposing partial imports.
-        mv -f -- "$partial" "$sqsh" || exit 1
-    ) || { echo "Error: enroot import failed for $image_ref -> $sqsh" >&2; return 1; }
+    test -r "$sqsh" || { echo "Error: squash file not readable: $sqsh" >&2; exit 1; }
 }
 
 if [[ "$IS_MULTINODE" == "true" ]]; then
@@ -214,15 +195,15 @@ SQUASH_FILE="$SQUASH_DIR/$(echo "$IMAGE" | sed 's/[\/:@#]/_/g').sqsh"
 NGINX_SQUASH_FILE="$SQUASH_DIR/$(echo "$NGINX_IMAGE" | sed 's/[\/:@#]/_/g').sqsh"
 
 # Import containers via enroot
-import_squash_image "$IMAGE" "$SQUASH_FILE" || exit 1
-import_squash_image "$NGINX_IMAGE" "$NGINX_SQUASH_FILE" || exit 1
+import_squash_image "$IMAGE" "$SQUASH_FILE"
+import_squash_image "$NGINX_IMAGE" "$NGINX_SQUASH_FILE"
 
 if [[ "$USES_DCGM_POWER" == "1" ]]; then
     DCGM_EXPORTER_IMAGE="nvcr.io/nvidia/k8s/dcgm-exporter:4.6.0-4.8.3-distroless"
     # enroot resolves bare paths against Docker Hub; nvcr.io pulls need the registry# form
     DCGM_EXPORTER_ENROOT_REF="${DCGM_EXPORTER_IMAGE/nvcr.io\//nvcr.io#}"
     DCGM_EXPORTER_SQSH="$SQUASH_DIR/$(echo "$DCGM_EXPORTER_IMAGE" | sed 's/[\/:@#]/_/g').sqsh"
-    import_squash_image "$DCGM_EXPORTER_ENROOT_REF" "$DCGM_EXPORTER_SQSH" || exit 1
+    import_squash_image "$DCGM_EXPORTER_ENROOT_REF" "$DCGM_EXPORTER_SQSH"
     sha256sum "$DCGM_EXPORTER_SQSH" > "$GITHUB_WORKSPACE/exporter-image.sha256"
 fi
 
@@ -486,7 +467,7 @@ else
         CONTAINER_MOUNT_DIR=/workspace
     fi
 
-    import_squash_image "$IMAGE" "$SQUASH_FILE" || exit 1
+    import_squash_image "$IMAGE" "$SQUASH_FILE"
 
     export GPU_COUNT="${GPU_COUNT:-${TP:?TP must be set}}"