2026.09.23 Release v0.7.2

CubeSandbox 0.7.2 introduces 3 major features along with multiple enhancements and bug fixes. 56 commits from 29 contributors.

🎯 Major Features

Much faster cross-node restore reads

Sandboxes restored cross-node on the S3 backend read disk data from S3 on demand; this release optimizes that read path systematically:

• New whole-object local cache: immutable data objects on S3 are kept on the local node, so repeated reads after a restore — and re-importing the same snapshot — hit the local cache instead of going back to S3.
• Reduced read amplification during restore: scattered small reads are coalesced into whole-object GETs, and the concurrent fetch budget is capped.
• With the default MinIO setup, cross-node restore / create-from-snapshot reaches running in under 1 second.

New JuiceFS volume plugin

New JuiceFS storage plugin: sandboxes can mount a JuiceFS filesystem as a persistent volume, with full POSIX semantics.

Automatic reclaim of idle guest memory

Idle memory inside sandboxes is reclaimed back to the host: node memory usage falls back dynamically with the real usage of the sandboxes, so a single node can host more sandboxes.

✨ Enhancements

Templates & Storage

• S3lvol hot upgrade: fixes the EIO errors seen inside sandboxes when upgrading the CubeS3lvol storage component.
• Local-filesystem storage for component repositories and template artifacts (#1749): component repositories and template artifacts can be stored on S3 / local disk / PVC / NFS.
• Incremental snapshot fix (#1343): fixed data loss in incremental snapshots.
• Faster virtiofs on the pause / snapshot path (#1748): optimized the state preparation flow before pause.
• Cubelet can configure the template install path, allowing large templates to be moved to the data disk (#1675).
• CubeS3lvol object cache: identical objects read during a cross-node restore are served from the local object cache first, and the object cache and dest cache share the same local cache storage (#1756).

Lifecycle & Control Plane

• sandbox.connect supports a timeout parameter (#1352).

Deployment & Runtime

• cube-node now runs on the host network by default in K8s deployments (#1815): recreating the cube-node Pod no longer destroys the network namespace, so the network of every sandbox on the node stays up. Switching an existing cluster requires draining compute nodes and explicit confirmation (hostNetworkChangeAck); fresh installs are unaffected.
• Faster sandbox cold start (#1694): disabled the RAID6 PQ startup benchmark in the guest kernel, which is unrelated to workloads.

Web UI / CubeOps / Other

• Removed the legacy E2B SDK reference; Python SDK command execution now goes through the envd Connect RPC (#1786).
• The Python SDK's run_code (E2B-compatible code-interpreter interface) can now read environment variables injected at sandbox creation (#1323), matching the behavior of commands.run; the new sandbox-code example image is required.

🐛 Bug Fixes

Lifecycle & Sandbox

• Fixed inconsistent memory-snapshot and image-snapshot state when building a template (#1760).
• Fixed existing snapshots becoming unusable after a template was deleted (#1763).
• Fixed a race where concurrent image builds left tasks stuck in BUILT with database connection timeouts (#1802).
• Fixed snapshot creation retries being rejected as a changed request body (#1253).
• Fixed paused sandboxes not returning a timeout (end_at=0) in Info / List queries (#1801).
• Fixed an explicit timeout passed to Connect not taking effect for already-running sandboxes; a shorter timeout no longer shortens an existing longer deadline, and the Python SDK now passes the parameter through (#1352).
• Fixed PVM detection: the upstream PVM ABI removed the CPUID signature, so detection now relies on the MSR list supported by KVM, compatible with both old and new ABIs (#1781).
• Fixed a kernel panic when PVM guests booted on Intel hosts because GMI sm3/sm4 probing was misdetected (#1725).
• Fixed resume failing after pause on ARM (Could not restore GICv3ITS state): the vgic state save was incorrectly optimized to all zeros by the compiler (#1658).

Networking & Security

• Fixed sandboxes having a guest MTU larger than the node uplink NIC under overlay CNI, which left the network broken out of the box: guest MTU now follows the node NIC automatically (it only decreases), and can be pinned with cubeNode.network.mtu (#1674).

Deployment & Upgrade

• Fixed the CUBE_SANDBOX_CUBE_EGRESS_IMAGE environment variable not being updated in .one-click.env for one-click deployments (#1788).
• Fixed CubeOps failing to connect when the MySQL password contains special characters; invalid configuration now fails at startup (#1617).
• Fixed one-click install failing silently on snap-packaged Docker; it now tells users to switch to docker-ce (#1789).
• Fixed inconsistent Redis logical-DB configuration across components in one-click deployments, which made CubeOps write metrics to the wrong database (#1705).
• Fixed PVM installation failing on Ubuntu (#1770).
• Fixed the template artifact cache not being movable to the data disk on its own (#1675).
• Fixed CubeS3lvol being pinned to CPU0/CPU1 by default; another CPU is now picked automatically when unconfigured (#1713).

Other

• Fixed PostgreSQL template-alias duplicate errors being misclassified by error text and occasional template status publish failures; classification now uses SQLSTATE (#1724).
• Fixed compatibility issues in the cubebench CPU topology report (#1757).
• Added an Ubuntu desktop sandbox example and integration guide (#1746).
• Added an OpenCode integration: a plugin hook redirects bash into the sandbox so commands no longer run directly on the developer's machine (#1238).
• Added a CI status page (#1737).
• Corrected the PVM expansion: Pagetable-based, not Parallel (#1772).
• Added a documentation security warning: injecting credentials over HTTP is unsafe, limited to controlled internal networks; prefer HTTPS (#1818).