Hi Ilya, On Thu, 5 Mar 2026, Ilya Dryomov via ceph-users wrote:
To see the image-level snapshots that comprise a group snapshot taken with "rbd group snap create", run "rbd snap ls --all". There is no support for cloning from a group snapshot directly but cloning from the corresponding image-level snapshots is possible with "rbd clone <image name> --snap-id <snap id>" syntax (instead of the usual "rbd clone <image name>@<snap name>"). As a workaround one can do that for each member image and then create a new group out of the resulting clone images. The new "clone" group wouldn't get linked to the original "parent" group like clone images get linked to their parent images though.
Thanks for this valuable information. I was able to clone each individual image from the group snapshot. Also found this IBM documentation[1].
Unfortunately there is no support for exporting a group snapshot directly (you already saw the unfinished PR) and even being able to export the corresponding image-level snapshots individually is pending on https://tracker.ceph.com/issues/72410. As a workaround one can clone from an image-level snapshot and then export the clone image.
Also confirming that exporting the cloned images works well. But with this workaround there seems no chance for export-diff between two group snapshots?
See my reply to Matthias -- involving qemu-guest-agent to freeze the filesystems before taking the snapshot is actually a superior option, so I wouldn't refer to it as a workaround.
Yes, immediately after sending, I realised that "workaround" is not the right wording. Of cause is fs-freezing the next right step into more consistent snapshots.
Thanks, Sascha. [1] https://www.ibm.com/docs/en/storage-ceph/9.9.0?topic=snapshot-cloning-block-device-group _______________________________________________ ceph-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
