Hi Dan, Just a quick addition here:I have not used the rados command to create the snapshot but "ceph osd pool mksnap $POOL $SNAPNAME" - which I think is the same internally?
And yes, our CephFS has numerous snapshots itself for backup purposes. Cheers, Pascal Dan van der Ster wrote on 24.06.22 11:06:
Hi Pascal, I'm not sure why you don't see that snap, and I'm also not sure if you can just delete the objects directly. BTW, does your CephFS have snapshots itself (e.g. create via mkdir .snap/foobar)? Cheers, Dan On Fri, Jun 24, 2022 at 10:34 AM Pascal Ehlert <pascal@xxxxxxxxxxxx> wrote:Hi Dan, Thank you so much for going through the effort of reproducing this! I was just about to plan how to bring up a test cluster but it would've taken me much longer. While I totally assume this is the root cause for our issues, there is one small difference. rados lssnap does not list any snapshots for me: root@srv01:~# rados lssnap -p kubernetes_cephfs_metadata 0 snaps I do definitely recall having made a snapshot and apparently there are snapshot objects present in the pool. Not sure how the reference seemingly got lost. Do you have any ideas how I could anyway remove the broken snapshot objects? Cheers, Pascal Dan van der Ster wrote on 24.06.22 09:27:Hi, It's trivial to reproduce. Running 16.2.9 with max_mds=2, take a pool snapshot of the meta pool, then decrease to max_mds=1, then deep scrub each meta pg. In my test I could list and remove the pool snap, then deep-scrub again cleared the inconsistencies. https://tracker.ceph.com/issues/56386 Cheers, Dan On Fri, Jun 24, 2022 at 8:41 AM Ansgar Jazdzewski <a.jazdzewski@xxxxxxxxxxxxxx> wrote:Hi, I would say yes but it would be nice if other people can confirm it too. also can you create a test cluster and do the same tasks * create it with octopus * create snapshot * reduce rank to 1 * upgrade to pacific and then try to fix the PG, assuming that you will have the same issues in your test-cluster, cheers, Ansgar Am Do., 23. Juni 2022 um 22:12 Uhr schrieb Pascal Ehlert <pascal@xxxxxxxxxxxx>:Hi, I have now tried to "ceph osd pool rmsnap $POOL beforefixes" and it says the snapshot could not be found although I have definitely run "ceph osd pool mksnap $POOL beforefixes" about three weeks ago. When running rados list-inconsistent-obj $PG on one of the affected PGs, all of the objects returned have "snap" set to 1: root@srv01:~# for i in $(rados list-inconsistent-pg $POOL | jq -er .[]); do rados list-inconsistent-obj $i | jq -er .inconsistents[].object; done [..] { "name": "200020744f4.00000000", "nspace": "", "locator": "", "snap": 1, "version": 5704208 } { "name": "200021aeb16.00000000", "nspace": "", "locator": "", "snap": 1, "version": 6189078 } [..] Running listsnaps on any of them then looks like this: root@srv01:~# rados listsnaps 200020744f4.00000000 -p $POOL 200020744f4.00000000: cloneid snaps size overlap 1 1 0 [] head - 0 Is it save to assume that these objects belong to a somewhat broken snapshot and can be removed safely without causing further damage? Thanks, Pascal Ansgar Jazdzewski wrote on 23.06.22 20:36: Hi, we could identify the rbd images that wehre affected and did an export before, but in the case of cephfs metadata i have no plan that will work. can you try to delete the snapshot? also if the filesystem can be shutdown? try to do a backup of the metadatapool hope you will have some luck, let me know if I can help, Ansgar Pascal Ehlert <pascal@xxxxxxxxxxxx> schrieb am Do., 23. Juni 2022, 16:45:Hi Ansgar, Thank you very much for the response. Running your first command to obtain inconsistent objects, I retrieve a total of 23114 only some of which are snaps. You mentioning snapshots did remind me of the fact however that I created a snapshot on the Ceph metadata pool via "ceph osd pool $POOL mksnap" before I reduced the number of ranks. Maybe that has causes the inconsistencies and would explain why the actual file system appears unaffected? Is there any way to validate that theory? I am a bit hesitant to just run "rmsnap". Could that cause inconsistent data to be written back to the actual objects? Best regards, Pascal Ansgar Jazdzewski wrote on 23.06.22 16:11:Hi Pascal, We just had a similar situation on our RBD and had found some bad data in RADOS here is How we did it: for i in $(rados list-inconsistent-pg $POOL | jq -er .[]); do rados list-inconsistent-obj $i | jq -er .inconsistents[].object.name| awk -F'.' '{print $2}'; done we than found inconsistent snaps on the Object: rados list-inconsistent-snapset $PG --format=json-pretty | jq .inconsistents[].name List the data on the OSD's (ceph pg map $PG) ceph-objectstore-tool --data-path /var/lib/ceph/osd/ceph-${OSD}/ --op list ${OBJ} --pgid ${PG} and finally remove the object, like: ceph-objectstore-tool --data-path /var/lib/ceph/osd/ceph-459/ --op list rbd_data.762a94d768c04d.000000000036b7ac --pgid 2.704ceph-objectstore-tool --data-path /var/lib/ceph/osd/ceph-459/ '["2.704",{"oid":"rbd_data.801e1d1d9c719d.0000000000044943","key":"","snapid":125458,"hash":4136961796,"max":0,"pool":2,"namespace":"","max":0}]' remove we had to do it for all OSD one after the other after this a 'pg repair' worked i hope it will help Ansgar Am Do., 23. Juni 2022 um 15:02 Uhr schrieb Dan van der Ster <dvanders@xxxxxxxxx>:Hi Pascal, It's not clear to me how the upgrade procedure you described would lead to inconsistent PGs. Even if you didn't record every step, do you have the ceph.log, the mds logs, perhaps some osd logs from this time? And which versions did you upgrade from / to ? Cheers, Dan On Wed, Jun 22, 2022 at 7:41 PM Pascal Ehlert <pascal@xxxxxxxxxxxx> wrote:Hi all, I am currently battling inconsistent PGs after a far-reaching mistake during the upgrade from Octopus to Pacific. While otherwise following the guide, I restarted the Ceph MDS daemons (and this started the Pacific daemons) without previously reducing the ranks to 1 (from 2). This resulted in daemons not coming up and reporting inconsistencies. After later reducing the ranks and bringing the MDS back up (I did not record every step as this was an emergency situation), we started seeing health errors on every scrub. Now after three weeks, while our CephFS is still working fine and we haven't noticed any data damage, we realized that every single PG of the cephfs metadata pool is affected. Below you can find some information on the actual status and a detailed inspection of one of the affected pgs. I am happy to provide any other information that could be useful of course. A repair of the affected PGs does not resolve the issue. Does anyone else here have an idea what we could try apart from copying all the data to a new CephFS pool? Thank you! Pascal root@srv02:~# ceph status cluster: id: f0d6d4d0-8c17-471a-9f95-ebc80f1fee78 health: HEALTH_ERR insufficient standby MDS daemons available 69262 scrub errors Too many repaired reads on 2 OSDs Possible data damage: 64 pgs inconsistent services: mon: 3 daemons, quorum srv02,srv03,srv01 (age 3w) mgr: srv03(active, since 3w), standbys: srv01, srv02 mds: 2/2 daemons up, 1 hot standby osd: 44 osds: 44 up (since 3w), 44 in (since 10M) data: volumes: 2/2 healthy pools: 13 pools, 1217 pgs objects: 75.72M objects, 26 TiB usage: 80 TiB used, 42 TiB / 122 TiB avail pgs: 1153 active+clean 55 active+clean+inconsistent 9 active+clean+inconsistent+failed_repair io: client: 2.0 MiB/s rd, 21 MiB/s wr, 240 op/s rd, 1.75k op/s wr { "epoch": 4962617, "inconsistents": [ { "object": { "name": "1000000cc8e.00000000", "nspace": "", "locator": "", "snap": 1, "version": 4253817 }, "errors": [], "union_shard_errors": [ "omap_digest_mismatch_info" ], "selected_object_info": { "oid": { "oid": "1000000cc8e.00000000", "key": "", "snapid": 1, "hash": 1369745244, "max": 0, "pool": 7, "namespace": "" }, "version": "4962847'6209730", "prior_version": "3916665'4306116", "last_reqid": "osd.27.0:757107407", "user_version": 4253817, "size": 0, "mtime": "2022-02-26T12:56:55.612420+0100", "local_mtime": "2022-02-26T12:56:55.614429+0100", "lost": 0, "flags": [ "dirty", "omap", "data_digest", "omap_digest" ], "truncate_seq": 0, "truncate_size": 0, "data_digest": "0xffffffff", "omap_digest": "0xe5211a9e", "expected_object_size": 0, "expected_write_size": 0, "alloc_hint_flags": 0, "manifest": { "type": 0 }, "watchers": {} }, "shards": [ { "osd": 20, "primary": false, "errors": [ "omap_digest_mismatch_info" ], "size": 0, "omap_digest": "0xffffffff", "data_digest": "0xffffffff" }, { "osd": 27, "primary": true, "errors": [ "omap_digest_mismatch_info" ], "size": 0, "omap_digest": "0xffffffff", "data_digest": "0xffffffff" }, { "osd": 43, "primary": false, "errors": [ "omap_digest_mismatch_info" ], "size": 0, "omap_digest": "0xffffffff", "data_digest": "0xffffffff" } ] }, _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx_______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx_______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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