Description of problem: With libvirt 0.8.3, when snapshots are linked to their parent snapshot, if the parent snapshot is deleted, the snapshot chain becomes broken. Deleting a child snapshot then terminates with an error message: error: Domain snapshot not found: no domain snapshot parent with matching name '1291813671' I can reproduce this using the following sequence of commands for my test-domain called "test" using a single qcow2 image: # virsh snapshot-create test # 1291813670 # virsh snapshot-create test # 1291813671 # virsh snapshot-create test # 1291813672 # virsh snapshot-delete test 1291813671 # virsh snapshot-delete test 1291813672 Reverting to such an unlinked snapshot is still possible, but deleting it doesn't work. Version-Release number of selected component (if applicable): 0.8.3. How reproducible: Every time. Expected results: The unlinked child snapshot should be deleted when requested, instead of generating the error message about a missing parent snapshot. Additional info: This error was reported by Philipp Hahn on the libvirt developers mailing list: https://www.redhat.com/archives/libvir-list/2010-December/msg00386.html
Philipp, how big a problem is this? Is it a matter of the snapshots hanging around, or does it prevent the guest from operating?
(In reply to comment #1) > Philipp, how big a problem is this? Is it a matter of the snapshots hanging > around, or does it prevent the guest from operating? Snapshots still work: I can revert back to them just fine. Only if I try to delete a snapshot whichs parent snapshot is already deleted, this operation fails. This is because the the snapshot contains a reference to the parent snapshot, which is than dangling. If I edit the snapshot file /var/lib/libvirt/qemu/snapshot/$VM_NAME/$SNAPSHOT_NAME.xml by hand and remove the danling /domainsnapshot/parent/name entity, I can than delete the snapshot using libvirt.
This has been fixed upsteam: https://www.redhat.com/archives/libvir-list/2010-December/msg00935.html