On Thu, Feb 18, 2021 at 03:28:11PM +0000, Eugen Block wrote: If your results shown below are not from that past then yes, it looks like the rbd-mirror (at least the image replayer) got stuck for some reason long time ago. Then I can't see though how could you mount a newly created snap, because it would not be replayed. Probably you had a snapshot with such name previously, it was replayed, then the rbd-mirror got stuck, the snapshot was deleted on the primary and a new one created recently. And on the secondary you was still seeing and mounting the old snapshot? This would also explain why you were able to mount it -- if data is really missing I expect you are not able to mount the fs due to corruption. If the rbd-mirror just got stuck then you probably don't need to resync. Just restarting the rbd-mirror should make it to start replaying again. Though taking how long it was not replaying, if the journal is very large, the resync might be faster. You can try: rbd journal info -p cifs --image research_data to see how large the journal is currently (the difference in the master and the rbd-mirror client positions). And if this is really the case that rbd-mirror got stuck, any additional info you could provide (rbd-mirror logs, the core dump) might be helpful for fixing the bug. It is can be reported right to the tracker. What version are you running BTW? -- Mykola Golub > Zitat von Vikas Rana <vrana(a)vtiersys.com>om>: > > > Hi Friends, > > > > > > > > We have a very weird issue with rbd-mirror replication. As per the command > > output, we are in sync but the OSD usage on DR side doesn't match the Prod > > Side. > > > > On Prod, we are using close to 52TB but on DR side we are only 22TB. > > > > We took a snap on Prod and mounted the snap on DR side and compared the data > > and we found lot of missing data. Please see the output below. > > > > > > > > Please help us resolve this issue or point us in right direction. > > > > > > > > Thanks, > > > > -Vikas > > > > > > > > DR# rbd --cluster cephdr mirror pool status cifs --verbose > > > > health: OK > > > > images: 1 total > > > > 1 replaying > > > > > > > > research_data: > > > > global_id: 69656449-61b8-446e-8b1e-6cf9bd57d94a > > > > state: up+replaying > > > > description: replaying, master_position=[object_number=390133, tag_tid=4, > > entry_tid=447832541], mirror_position=[object_number=390133, tag_tid=4, > > entry_tid=447832541], entries_behind_master=0 > > > > last_update: 2021-01-29 15:10:13 > > > > > > > > DR# ceph osd pool ls detail > > > > pool 5 'cifs' replicated size 2 min_size 1 crush_rule 0 object_hash rjenkins > > pg_num 128 pgp_num 128 last_change 1294 flags hashpspool stripe_width 0 > > application rbd > > > > removed_snaps [1~5] > > > > > > > > > > > > PROD# ceph df detail > > > > POOLS: > > > > NAME ID QUOTA OBJECTS QUOTA BYTES USED %USED > > MAX AVAIL OBJECTS DIRTY READ WRITE RAW USED > > > > cifs 17 N/A N/A 26.0TiB 30.10 > > 60.4TiB 6860550 6.86M 873MiB 509MiB 52.1TiB > > > > > > > > DR# ceph df detail > > > > POOLS: > > > > NAME ID QUOTA OBJECTS QUOTA BYTES USED %USED > > MAX AVAIL OBJECTS DIRTY READ WRITE RAW USED > > > > cifs 5 N/A N/A 11.4TiB 15.78 > > 60.9TiB 3043260 3.04M 2.65MiB 431MiB 22.8TiB > > > > > > > > > > > > > > > > PROD#:/vol/research_data# du -sh * > > > > 11T Flab1 > > > > 346G KLab > > > > 1.5T More > > > > 4.4T ReLabs > > > > 4.0T WLab > > > > > > > > DR#:/vol/research_data# du -sh * > > > > 2.6T Flab1 > > > > 14G KLab > > > > 52K More > > > > 8.0K RLabs > > > > 202M WLab > > > > _______________________________________________ > > ceph-users mailing list -- ceph-users(a)ceph.io > > To unsubscribe send an email to ceph-users-leave(a)ceph.io > > > _______________________________________________ > ceph-users mailing list -- ceph-users(a)ceph.io > To unsubscribe send an email to ceph-users-leave(a)ceph.io

Hello Mykola/Eugen, Here's the output. We also restarted the rbd-mirror process # rbd journal info -p cifs --image research_data rbd journal '11cb6c2ae8944a': header_oid: journal.11cb6c2ae8944a object_oid_prefix: journal_data.17.11cb6c2ae8944a. order: 24 (16MiB objects) splay_width: 4 We restarted the rbd-mirror process on the DR side # rbd --cluster cephdr mirror pool status cifs --verbose health: OK images: 1 total 1 replaying research_data: global_id: 69656449-61b8-446e-8b1e-6cf9bd57d94a state: up+replaying description: replaying, master_position=[object_number=396351, tag_tid=4, entry_tid=455084955], mirror_position=[object_number=396351, tag_tid=4, entry_tid=455084955], entries_behind_master=0 last_update: 2021-02-19 15:36:30 Thanks, -Vikas -----Original Message----- From: Vikas Rana <vrana(a)vtiersys.com> Sent: Friday, February 19, 2021 2:00 PM To: 'Mykola Golub' <to.my.trociny(a)gmail.com>om>; 'Eugen Block' <eblock(a)nde.ag> Cc: ceph-users(a)ceph.io Subject: [ceph-users] Re: Data Missing with RBD-Mirror Hello Mykola and Eugen, There was no interruption and we are in a campus with 10G backbone. We are on 12.2.10 I believe. We wanted to check the data on DR side and then we created a snapshot on primary which was available on DR side very quickly. It kind of gave me feeling that rbd-mirror is not stuck. I will run those commands and also restart the rbd-mirror and will report back. Thanks, -Vikas -----Original Message----- From: Mykola Golub <to.my.trociny(a)gmail.com> Sent: Thursday, February 18, 2021 2:51 PM To: Vikas Rana <vrana(a)vtiersys.com>om>; Eugen Block <eblock(a)nde.ag> Cc: ceph-users(a)ceph.io Subject: Re: [ceph-users] Re: Data Missing with RBD-Mirror On Thu, Feb 18, 2021 at 03:28:11PM +0000, Eugen Block wrote: If your results shown below are not from that past then yes, it looks like the rbd-mirror (at least the image replayer) got stuck for some reason long time ago. Then I can't see though how could you mount a newly created snap, because it would not be replayed. Probably you had a snapshot with such name previously, it was replayed, then the rbd-mirror got stuck, the snapshot was deleted on the primary and a new one created recently. And on the secondary you was still seeing and mounting the old snapshot? This would also explain why you were able to mount it -- if data is really missing I expect you are not able to mount the fs due to corruption. If the rbd-mirror just got stuck then you probably don't need to resync. Just restarting the rbd-mirror should make it to start replaying again. Though taking how long it was not replaying, if the journal is very large, the resync might be faster. You can try: rbd journal info -p cifs --image research_data to see how large the journal is currently (the difference in the master and the rbd-mirror client positions). And if this is really the case that rbd-mirror got stuck, any additional info you could provide (rbd-mirror logs, the core dump) might be helpful for fixing the bug. It is can be reported right to the tracker. What version are you running BTW? -- Mykola Golub command Prod data tag_tid=4, rjenkins %USED 30.10 %USED 15.78 _______________________________________________ ceph-users mailing list -- ceph-users(a)ceph.io To unsubscribe send an email to ceph-users-leave(a)ceph.io

That is correct. On Prod we do have 22TB and on DR we only have 5.5TB Thanks, -Vikas -----Original Message----- From: Mykola Golub <to.my.trociny(a)gmail.com> Sent: Monday, February 22, 2021 10:47 AM To: Vikas Rana <vrana(a)vtiersys.com> Cc: 'Eugen Block' <eblock(a)nde.ag>ag>; ceph-users(a)ceph.io; dillaman(a)redhat.com Subject: Re: [ceph-users] Re: Data Missing with RBD-Mirror On Mon, Feb 22, 2021 at 09:41:44AM -0500, Vikas Rana wrote: Eh, I asked for a wrong command. Actually I wanted to see `rbd journal status`. Anyway, I have that info in mirror status below, which looks like up to date now. entries_behind_master=0 And I suppose, after creating and replaying a snapshot, you still see files missing on the secondary after mounting it? -- Mykola Golub

We did compare and it was missing lot of data. I'll issue resync and report back. Thanks, -Vikas -----Original Message----- From: Mykola Golub <to.my.trociny(a)gmail.com> Sent: Monday, February 22, 2021 12:09 PM To: Vikas Rana <vrana(a)vtiersys.com> Cc: 'Mykola Golub' <to.my.trociny(a)gmail.com>om>; 'Eugen Block' <eblock(a)nde.ag>ag>; ceph-users(a)ceph.io; dillaman(a)redhat.com Subject: Re: [ceph-users] Re: Data Missing with RBD-Mirror On Mon, Feb 22, 2021 at 11:37:52AM -0500, Vikas Rana wrote: But did you check that you really have missing files/data? Just to make sure it is not just some issue with how data is stored/counted in different clusters. Assuming you did and data is missing, then the only way to proceed I think is to issue resync, running on the secondary site: rbd mirror image resync cifs/research_data Note, it would mean recreating the image and resyncing all 22TB though. And it would be nice to add some monitoring to be able to detect the moment if the issue happens again, and report it to the tracker attaching the rbd-mirror logs. -- Mykola Golub