[libvirt-users] VM with ceph backend snapshot-revert error

[Josh Durgin]

On 09/24/2013 01:02 AM, 王根意 wrote:
> Hey guys:
>
> I have a running vm with ceph backend:
>
>     root at apc20-005:~# virsh list
>       Id Name                 State
>     ----------------------------------
>       56 one-240              running
>
>
> And *snapshot-create-as* works well:
>
>     root at apc20-005:~# virsh snapshot-create-as one-240
>     Domain snapshot 1380009353 created
>
>
> But when exec *snapshot-revert*, error occurs:
>
>     root at apc20-005:~# virsh snapshot-revert one-240 1380009353
>     *error: operation failed: Error -22 while loading VM state*
>
>
> And the vm went paused state.
>
>     root at apc20-005:~# virsh list
>       Id Name                 State
>     ----------------------------------
>       56 one-240              paused
>
>
>
> When I use qcow2 image backend, Everything is ok! Any idea?

This happens because libvirt/qemu try to load the memory state of the
vm, in addition to the disk state. RBD only saves the disk state, so
attempting to load the memory state fails.

There's a feature request for improving this [1].

You can revert the disk directly with the 'rbd rollback' command
instead.

Josh

[1] http://tracker.ceph.com/issues/2773