RBD volume with parent cannot be used after restore about backy2 HOT 4 OPEN

backy2 does not care about any relationships in the storage volumes. It knows nothing about it, and this is a design choice. It just stores blocks.
How have you created the backups?

from backy2.

I do the backup as follows:

rbd snap create rbd/c1bb66e1-030f-48a0-94b5-74910333cd49@backup1
rbd diff --whole-object rbd/c1bb66e1-030f-48a0-94b5-74910333cd49@backup1 --format=json > /root/backup1.diff
backy2 backup -s backup1 -r /root/backup1.diff rbd://rbd/c1bb66e1-030f-48a0-94b5-74910333cd49@backup1 c1bb66e1-030f-48a0-94b5-74910333cd49

Use this backup to restore to a new RBD [root-101]
RBD [root-101] cannot be used normally and the data is incomplete

If I execute the following command first
rbd flatten rbd/c1bb66e1-030f-48a0-94b5-74910333cd49

Then take a snapshot, diff, backup

This backup can be restored and used normally

from backy2.

I wish I knew about this bug before today. I’ve lost a whole pool and now find that any vm images that were cloned from a base image cannot be recovered. Not a production environment but still lost 20 VMs from my home lab.

from backy2.

This is most likely a bug in Ceph. Probably this one: https://tracker.ceph.com/issues/54970. If you're stuck on an older version try leaving off --whole-object from the rbd diff call as a workaround. But this will slow down the rbd diff.

from backy2.