Hi, my environment is: Epoxy on Ubuntu 24.04 package-based installation I'm looking for some clarification regarding this bug report [0]. I don't really understand if it's fixed or not. I was trying to rollback a volume to its backup version when I got this stack trace: Backup service: cinder.backup.drivers.ceph.CephBackupDriver. 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server [None req-54d97a73-522d-411a-9982-1f6bb0ea905b 89c5dcc8793d4867bae22d50e51e16b3 90c403f317ee47feb0dad58461e76fb1 - - - -] Exception during message handling: TypeError: BackupManager.restore_backup() missing 1 required positional argument: 'volume_is_new' 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server Traceback (most recent call last): 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/server.py", line 174, in _process_incoming 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message) 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/dispatcher.py", line 309, in dispatch 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args) 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/dispatcher.py", line 229, in _do_dispatch 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args) 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server ^^^^^^^^^^^^^^^^^^^^^^ 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/cinder/utils.py", line 1053, in wrapper 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server return func(self, *args, **kwargs) 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2026-03-17 08:37:02.805 1516544 ERROR oslo_messaging.rpc.server TypeError: BackupManager.restore_backup() missing 1 required positional argument: 'volume_is_new' It's stated that it was fixed in cinder versions 22 and 23, we are on Epoxy (cinder v 26) and still hit that issue. I then manually applied [1] which seems to have fixed the "volume_is_new" issue, at least I can restore volumes now. But I was also wondering why it took so long, and noticed that it doesn't keep the sparseness (although it should according to [2]. Here's the 'rbd du' output from a successfully restored volume: rbd du volumes-ssd/volume-6a9a8497-eacd-490e-be3e-f6dbdf638b5d NAME PROVISIONED USED volume-6a9a8497-eacd-490e-be3e-f6dbdf638b5d@backup.db61467a-5c29-4fca-b393-a1962dc6d2a8.snap.1773736256.760678 40 GiB 4.9 GiB volume-6a9a8497-eacd-490e-be3e-f6dbdf638b5d 40 GiB 40 GiB <TOTAL> 40 GiB 45 GiB I didn't expect that. Could anyone help me understand? Thanks! Eugen [0] https://bugs.launchpad.net/cinder/+bug/2025277 [1] https://review.opendev.org/c/openstack/cinder/+/914775 [2] https://bugs.launchpad.net/cinder/+bug/2007615