Cold mode

Cold mode is the product-level lifecycle state for a sandbox that is not running but can be recovered from saved state.

In mvm, cold mode maps to backend-specific snapshot mechanisms. It is a lifecycle state, not a separate runtime.

mvm model

Running microVM
  -> pause/save snapshot
  -> cold state on disk
  -> resume/restore
  -> Running microVM

The runtime primitive is mvm: it knows how to talk to the backend, write or verify the snapshot artifact, and restore the guest. The exact artifact depends on the backend.

What users need to know

Question	Answer
Is cold state free?	No. It consumes storage and may contain sensitive guest state.
Is restore universal?	No. Backend support differs.
Is restore a security boundary?	No. It is a lifecycle feature; isolation still comes from the microVM/backend and policy layers.
Can cold mode be fast?	It can be faster than a fresh build-plus-boot path, but published numbers must state backend and readiness boundary.

Required docs language

Use “cold mode” for the product state. Use backend-specific terms for implementation:

• Firecracker sealed pause/resume.
• Vz machine-state save/restore.
• Pool Sleeping/Running restore. Avoid implying that every backend supports every cold-mode operation.