2010/12/8 Philipp Hahn <hahn@univention.de>:

Hello,

I encountered another problem: snapshots are linked to there parent snapshot. If the parent snapshot is deleted, the chain gets broken and deleting the child snapshot 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 singel 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

Is this problem known (libvirt-0.8.3)? Reverting to such an unlinked snapshot is still possible, but deleting it is not.

Sorry for the late response. I can reproduce this with current git head. The problem is that the QEMU driver doesn't update the parent attribute of the children of a snapshot being deleted. While looking at the code there are other problems too. For example, which snapshot is the current one it not saved to disk. Therefore, when you create a snapshot A and after this another snapshot B you should get A <- [B] where X <- Y means X is parent of Y and [Z] means current snapshot. But when you restart libvirtd in between creating A and B then you end up with A [B] Anyway, I've posted a patch that fixes the problem you reported by updating the parent attribute of the children of a snapshot being deleted. https://www.redhat.com/archives/libvir-list/2010-December/msg00935.html Matthias