On Mon, Aug 28, 2023 at 6:21 AM Tony Liu <tonyliu0592@hotmail.com> wrote:
It's export-diff from an in-use image, both from-snapshot and to-snapshot exist. The same from-snapshot exists in import image, which is the to-snapshot from last diff. export/import is used for local backup, rbd-mirroring is used for remote backup.
Just to make it clear, do you mean you are running export-diff for an image that is being mirrored (snapshot based)?
Looking for options to get more info to troubleshoot.
I would split "rbd export-diff | rbd import-diff" into two commands: rbd export-diff > image.diff rbd import-diff < image.diff and see if it gets stuck for the first one, so we are sure the export-diff is the issue here. The next step would be enabling rbd debug, something like this: rbd export-diff .. --debug-rbd=20 --log-file=/tmp/{image}_{from_snap}_{to_snap}.log --log-to-stderr=false Hope it will not use too much space and you will be able to get a log for a getting stuck case. Then please provide the log for review somehow. Also, notice the time when you interrupt the hanging export-diff. -- Mykola Golub