Partial online disk migration between non-matching hardware

[pkramme]

Please confirm

• I have searched existing issues to check if an issue already exists for my feature request.

Is your feature request related to a problem? Please describe.

Today we had the unfortunate situation where we had to migrate a virtual machine between non matching hypervisors. As far as I can see I have one option: lxc stop myvm, lxc move oldhypervisor:myvm myvm, lxc start myvm. This then means that the VM is not running as long as the migration takes.

Describe the solution you'd like

It would be awesome if we could have the option to start the migration, sync the disk online, shutdown the VM, move the VM, and start, as one command. This would leave the VM running as long as possible, while still making it possible to move the VM between nonmatching hardware.

Describe alternatives you've considered

• Just moving a snapshot, but that misses data that is written to the old VM
• Matching hardware, but that's not always an option, especially during infra updates

Additional context

No response

[tomponline]

You could do:

lxc snapshot v1
lxc copy --refresh --allow-inconsistent v1 newremote:
lxc stop v1
lxc copy --refresh v1 newremote:

Depending on the storage driver being used, this will only copy the differences between the first snapshot and the current running state of the VM after lxc stop v1 is run.