Hello all! Hope that anybody can help us. The initial point: Ceph cluster v15.2 (installed and controlled by the Proxmox) with 3 nodes based on physical servers rented from a cloud provider. The volumes provided by Ceph using CephFS and RBD also. We run 2 MDS daemons but use max_mds=1 so one daemon was in active state, and another in standby. On Thursday some of the applications stopped working. After the investigation it was clear that we have a problem with Ceph, more precisely with СephFS - both MDS daemons suddenly crashed. We tried to restart them and found that they crashed again immediately after the start. The crash information: 2024-04-17T17:47:42.841+0000 7f959ced9700 1 mds.0.29134 recovery_done -- successful recovery! 2024-04-17T17:47:42.853+0000 7f959ced9700 1 mds.0.29134 active_start 2024-04-17T17:47:42.881+0000 7f959ced9700 1 mds.0.29134 cluster recovered. 2024-04-17T17:47:43.825+0000 7f959aed5700 -1 ./src/mds/OpenFileTable.cc: In function 'void OpenFileTable::commit(MDSContext*, uint64_t, int)' thread 7f959aed5700 time 2024-04-17T17:47:43.831243+0000 ./src/mds/OpenFileTable.cc: 549: FAILED ceph_assert(count > 0) Next hours we read tons of articles, studied the documentation, and checked the cluster status in general by the various diagnostic commands - but didn't find anything wrong. At evening we decided to upgrade our Ceph cluster; so, we upgraded it to v16, and finally to v17.2.7. Unfortunately, it didn't solve the problem, MDS continue to crash with the same error. The only difference that we found is the "1 MDSs report damaged metadata" in the output of ceph -s - see it below. I supposed that it may be the well-known bug, but couldn't find the same one on https://tracker.ceph.com - there are several bugs associated with file OpenFileTable.cc but not related to ceph_assert(count > 0) We tried to check the source code of OpenFileTable.cc also, here is a fragment of it, in function OpenFileTable::_journal_finish int omap_idx = anchor.omap_idx; unsigned& count = omap_num_items.at(omap_idx); ceph_assert(count > 0); So, we guess that the object map is empty for some object in Ceph, and it is unexpected behavior. But again, we found nothing wrong in our cluster... Next, we started with https://docs.ceph.com/en/latest/cephfs/disaster-recovery-experts/ article - tried to reset the journal (despite that it was Ok all the time) and wipe the sessions using cephfs-table-tool all reset session command. No result... Now I decided to continue following this article and run cephfs-data-scan scan_extents command, we started it on Friday but it is still working (2 from 3 workers finished, so I'm waiting for the last one; may be I need more workers for the next command cephfs-data-scan scan_inodes that I plan to run ). But I have a doubt that it will solve the issue because, again, we guess that we have no problem with our objects in Ceph but with metadata only... Is it the new bug? or something else? What should we try additionally to run our MDS daemon? Any idea is welcome! The important outputs: ceph -s cluster: id: 4cd1c477-c8d0-4855-a1f1-cb71d89427ed health: HEALTH_ERR 1 MDSs report damaged metadata insufficient standby MDS daemons available 83 daemons have recently crashed 3 mgr modules have recently crashed services: mon: 3 daemons, quorum asrv-dev-stor-2,asrv-dev-stor-3,asrv-dev-stor-1 (age 22h) mgr: asrv-dev-stor-2(active, since 22h), standbys: asrv-dev-stor-1 mds: 1/1 daemons up osd: 18 osds: 18 up (since 22h), 18 in (since 29h) data: volumes: 1/1 healthy pools: 5 pools, 289 pgs objects: 29.72M objects, 5.6 TiB usage: 21 TiB used, 47 TiB / 68 TiB avail pgs: 287 active+clean 2 active+clean+scrubbing+deep io: client: 2.5 KiB/s rd, 172 KiB/s wr, 261 op/s rd, 195 op/s wr ceph fs dump e29480 enable_multiple, ever_enabled_multiple: 0,1 default compat: compat={},rocompat={},incompat={1=base v0.20,2=client writeable ranges,3=default file layouts on dirs,4=dir inode in separate object,5=mds uses versioned encoding,6=dirfrag is stored in omap,7=mds uses inline data,8=no anchor table,9=file layout v2,10=snaprealm v2} legacy client fscid: 1 Filesystem 'cephfs' (1) fs_name cephfs epoch 29480 flags 12 joinable allow_snaps allow_multimds_snaps created 2022-11-25T15:56:08.507407+0000 modified 2024-04-18T16:52:29.970504+0000 tableserver 0 root 0 session_timeout 60 session_autoclose 300 max_file_size 1099511627776 required_client_features {} last_failure 0 last_failure_osd_epoch 14728 compat compat={},rocompat={},incompat={1=base v0.20,2=client writeable ranges,3=default file layouts on dirs,4=dir inode in separate object,5=mds uses versioned encoding,6=dirfrag is stored in omap,7=mds uses inline data,8=no anchor table,9=file layout v2,10=snaprealm v2} max_mds 1 in 0 up {0=156636152} failed damaged stopped data_pools [5] metadata_pool 6 inline_data disabled balancer standby_count_wanted 1 [mds.asrv-dev-stor-1{0:156636152} state up:active seq 6 laggy since 2024-04-18T16:52:29.970479+0000 addr [v2:172.22.2.91:6800/2487054023,v1:172.22.2.91:6801/2487054023] compat {c=[1],r=[1],i=[7ff]}] cephfs-journal-tool --rank=cephfs:0 journal inspect Overall journal integrity: OK ceph pg dump summary version 41137 stamp 2024-04-18T21:17:59.133536+0000 last_osdmap_epoch 0 last_pg_scan 0 PG_STAT OBJECTS MISSING_ON_PRIMARY DEGRADED MISPLACED UNFOUND BYTES OMAP_BYTES* OMAP_KEYS* LOG DISK_LOG sum 29717605 0 0 0 0 6112544251872 13374192956 28493480 1806575 1806575 OSD_STAT USED AVAIL USED_RAW TOTAL sum 21 TiB 47 TiB 21 TiB 68 TiB ceph pg dump pools POOLID OBJECTS MISSING_ON_PRIMARY DEGRADED MISPLACED UNFOUND BYTES OMAP_BYTES* OMAP_KEYS* LOG DISK_LOG 8 31771 0 0 0 0 131337887503 2482 140 401246 401246 7 839707 0 0 0 0 3519034650971 736 61 399328 399328 6 1319576 0 0 0 0 421044421 13374189738 28493279 206749 206749 5 27526539 0 0 0 0 2461702171417 0 0 792165 792165 2 12 0 0 0 0 48497560 0 0 6991 6991 --- Best regards, Alexey Gerasimov System Manager www.opencascade.com<http://www.opencascade.com/> www.capgemini.com<http://www.capgemini.com> [cid:image001.png@01DA93D0.B001CE80]
