Move a machine to another host

Any stopped machine — classic VM or AppVM — can leave one host and arrive on another as a single file, downloaded and uploaded through the console. No SSH, no mount points, and no host paths to know.

Export

Open the machine, and choose More → Export transfer package. It stays disabled until the machine is completely stopped, because its disks cannot be copied consistently while they are open.

The host builds one .virtainer-vm package and your browser downloads it. Inside are the machine’s configuration, its root disk, every attached data volume, registered volume metadata, the machine’s snapshots, and the credentials it needs to run. Cached images, metrics, and logs stay behind.

The host does not keep a copy

The package is staged on the host only until your download finishes. It is also discarded after 15 minutes, and on the next restart of Virtainer Free. Your browser is the only courier, and the file on your computer is the only copy.

Import

On the destination host, open Instances and choose Import, then drop the .virtainer-vm file in.

1. Upload the package. The dialog shows progress while it transfers.

2. Let the host take over. Once the upload completes, the import continues on the host on its own. You can close the dialog and follow it in Operations.

3. Check it before booting. The machine arrives Powered off. Confirm the destination host actually has the network, CPU affinity, and PCI devices it expects, then boot it.

What import guarantees

The machine arrives as the same machine, not a copy of it: same id, same MAC addresses, same volume identities, same CPU and memory, same network and cloud-init configuration.

Import never overwrites anything

If any of that identity already exists on the destination — the machine id, a MAC address, a registered volume, a disk file — the import is refused. It does not overwrite, it does not merge, and it does not quietly rename things to fit.

That makes transfer the right tool for moving a machine and the wrong tool for cloning one. To run two copies at once you want a fresh machine from a template or an image, not a second import.

Packages are also version-locked: a package only imports into the same version of Virtainer Free that produced it. Move machines before you upgrade, or upgrade both hosts first.

This is not a backup

A transfer package has no retention, no compatibility promise across versions, and nothing on the host to fall back to once you have downloaded it. If the file on your computer is lost, it is simply gone.

For copies you intend to keep, see Backup and restore.

If something goes wrong

Both hosts check that they have room before they commit to anything — a package too large for the destination is refused before any disk is written, not half-way through.

If Virtainer Free restarts mid-import, the operation is left marked Uncertain rather than guessed at. Open Operations and use Recheck: it resumes from the package it already has and finishes, or tells you it could not.

Who can do it

Import and export are available to a signed-in administrator only, and are deliberately excluded from API keys. A transfer package carries a whole machine including its credentials, which is not something an automated key should be able to move on its own. See API keys.