fuse snapshot create

Snapshot a running environment

fuse snapshot create <vm-id> [flags]

Creates a snapshot of the given environment (VM). Three preconditions apply:

• the VM must be running
• the provider must support snapshots, GPU environments have no snapshot support at all (a vfio passthrough device cannot be checkpointed), see Snapshots
• the tenant must be under both its snapshot count and byte quotas

A quota rejection, a not-running VM, and the GPU guardrail all return 409 / conflict. A provider with no snapshot support at all returns 501 / unimplemented. All of these are permanent properties of the request, so none of them should be retried.

Flags

--live

Without it, the snapshot is disk-only: the rootfs is copied and nothing else, and restoring it cold-boots the guest. The record’s kind is disk.

With it, the VM is paused and the guest’s memory and vCPU state are written alongside the rootfs copy, inside a single pause window so the disk matches the memory. The record’s kind is live, and restoring it resumes the guest instead of booting it. fuse snapshot restore takes no corresponding flag; it reads the kind off the snapshot.

Four things to know before using it:

• it costs the environment’s full configured memory in bytes on every create, and per-tenant byte quotas were calibrated for rootfs-only snapshots
• the guest is paused for the duration of the capture
• it cannot be forked from. fuse environment fork reads only the rootfs, so a fork of a live snapshot cold-boots without the memory
• it is pinned to the host that took it. A memory image depends on that host’s CPU model and Firecracker version, and does not travel

--live against a backend with no live-snapshot support returns 501 / unimplemented, with a message telling you to retry without it. And the kind recorded on the snapshot is what the host agent reports it actually wrote, not what you asked for, so a host running an agent too old to know about live snapshots answers a live request with a disk snapshot. Check the kind rather than assuming. See Snapshots.

Examples

fuse snapshot create fuse-abc123 --comment "before risky migration" --mode manual

fuse snapshot create fuse-abc123 --live --comment "warmed model loaded"

Interactive mode

With a TTY and none of --comment, --mode, --retention, or --export-ref set, comment/mode/retention are collected via a form instead of flags. --metadata is not part of that check, passing it alone does not suppress the form.