docs(sandboxes): virtiofs cache is now enabled by default on macOS and Linux

Direct-mode virtiofs caching is now on by default on macOS and Linux;
Windows remains opt-in. Corrected the troubleshooting guidance, which
still described caching as disabled by default, and documented
DOCKER_SANDBOXES_ENABLE_VIRTIOFS_CACHE=0 as the kill switch.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
David Karlsson
2026-06-15 13:50:22 +02:00
parent 07e45f0483
commit 5f50b58765
@@ -183,20 +183,24 @@ Extracting the tar archive as the current user avoids the `chown` call.
Filesystem operations such as `git status`, `git log`, or directory scans can
be noticeably slow when the sandbox workspace is mounted in direct mode (the
default for workspaces without `--clone`). In direct mode, virtiofs caching is
disabled by default to prevent data corruption. Clone-mode sandboxes enable
virtiofs caching automatically, so this tuning applies only to direct mode.
default for workspaces without `--clone`). Virtiofs caching speeds up these
workloads. Clone-mode sandboxes always enable it, so this tuning applies only
to direct mode.
To speed up filesystem-intensive workloads, opt into virtiofs caching when
creating the sandbox:
On macOS and Linux, virtiofs caching is enabled by default. On Windows it's
still opt-in — enable it when creating the sandbox:
```console
$ DOCKER_SANDBOXES_ENABLE_VIRTIOFS_CACHE=1 sbx run <template>
```
The setting is persisted in the sandbox spec and applies for the lifetime of
that sandbox. If you experience Git index corruption or unexpected file content
after enabling the cache, remove the sandbox and recreate it without the flag.
that sandbox. If you experience Git index corruption or unexpected file content,
disable caching with the kill switch and recreate the sandbox:
```console
$ DOCKER_SANDBOXES_ENABLE_VIRTIOFS_CACHE=0 sbx run <template>
```
## Clone mode reports "not in a Git repository" on WSL