Re: [libvirt] [BUG] intermediate snapshot deleted
2010/12/8 Philipp Hahn <hahn(a)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