On 04/05/2018 10:26, Kashyap Chamarthy wrote:
Yes, you still have to clean up external snapshot metadata manually, as the link below indicates. Deleting external snapshots is a non-trivial problem. For example, if you have a disk image chain like:
[A] <-- [B] <-- [C] <-- [D]
Now if you no longer need image [B], what is the most efficient way to get rid of it? Three possibilities:
- Merge [B] into [A], and rewrite the backing chain of [C] to point to [A]. Now can you discard image [B]. - Merge [A] into [B], call the new image [AB]. Now you can discard [A]. - Merge [B] into [C], and rewrite the backing chain of [C] to point to [A]. Now you can discard image [B].
It depends on how large each of the disk images are, and based on the size, merge / coalesce them accordingly, to arrive at the quickest solution.
True.
Note that existing commands (`virsh blockpull` and `virsh blockcommit`, which is relatively faster) will allow you handle it manually or script it -- which many people already do it. > A couple of references (that are also easily scriptable):
http://wiki.libvirt.org/page/Live-merge-an-entire-disk-image-chain-including... https://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit
[1] https://www.redhat.com/archives/libvirt-users/2015-September/msg00037.html
Any hope to get virsh external snapshot creation/deletion fixed?
I don't see any problem creation external snapshots (or more correctly: "overlays"). Deletion of external snapshots involves a bit more work, but it is scriptable as well.
Reading old mailing list posts, I was under impression that some work was put to automatically and trasparently issue the best blockpull/blockcommit command. If not - fair enough ;) Thanks. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8