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