The 4 GiB cap on the writable overlay gets tight once one installs a normal toolchain (for longer-lived sandboxes). Bind-mounts and /tmp do cover some writes but not everything. Currently working around it by baking more things into the OCI image.
Ext4FormatOptions::size_bytes already exists and format_ext4_with_tree honours it. The only caller create_upper_ext4 in crates/microsandbox/lib/sandbox/mod.rs always passes Ext4FormatOptions::default(), pinning it to DEFAULT_SIZE_BYTES = 4 * 1024 * 1024 * 1024 (crates/image/lib/ext4/mod.rs:25). Nothing in SandboxConfig, the builder, the CLI, or SandboxDefaults exposes the field.
Environment: msb 0.4.6, WSL2 Ubuntu 24.04.2 LTS
Proposal: sandbox-level knob (builder method / CLI flag / SandboxDefaults entry) for upper-layer size, default unchanged.
PS: happy to send a PR if this seems like a reasonable request
The 4 GiB cap on the writable overlay gets tight once one installs a normal toolchain (for longer-lived sandboxes). Bind-mounts and
/tmpdo cover some writes but not everything. Currently working around it by baking more things into the OCI image.Ext4FormatOptions::size_bytesalready exists andformat_ext4_with_treehonours it. The only callercreate_upper_ext4incrates/microsandbox/lib/sandbox/mod.rsalways passesExt4FormatOptions::default(), pinning it toDEFAULT_SIZE_BYTES = 4 * 1024 * 1024 * 1024(crates/image/lib/ext4/mod.rs:25). Nothing inSandboxConfig, the builder, the CLI, orSandboxDefaultsexposes the field.Environment: msb 0.4.6, WSL2 Ubuntu 24.04.2 LTS
Proposal: sandbox-level knob (builder method / CLI flag /
SandboxDefaultsentry) for upper-layer size, default unchanged.PS: happy to send a PR if this seems like a reasonable request