Hi guys, I have a ceph cluster with three MDS servers, two of them in active status, while the left one is in standby-replay mode. Today I found the message '1 MDSs are read only' show up when check the cluster status with 'ceph -s', details as below: # ceph -s cluster: id: 3d43e9a5-50dc-4f84-9493-656bf4f06f8c health: HEALTH_WARN 5 clients failing to advance oldest client/flush tid 1 MDSs are read only 2 MDSs report slow requests 2 MDSs behind on trimming BlueFS spillover detected on 33 OSD(s) services: mon: 3 daemons, quorum bjcpu-001,bjcpu-002,bjcpu-003 (age 3M) mgr: bjcpu-001.xxxx.io(active, since 3M), standbys: bjcpu-003.xxxx.io, bjcpu-002.xxxx.io mds: cephfs:2 {0=bjcpu-003.xxxx.io=up:active,1=bjcpu-001.xxxx.io=up:active} 1 up:standby-replay osd: 48 osds: 48 up (since 7w), 48 in (since 7M) data: pools: 3 pools, 2304 pgs objects: 301.35M objects, 70 TiB usage: 246 TiB used, 280 TiB / 527 TiB avail pgs: 2295 active+clean 9 active+clean+scrubbing+deep io: client: 254 B/s rd, 44 MiB/s wr, 0 op/s rd, 15 op/s wr What should I do to fix the error message? it seems the cluster still works fine(can read and write). Many thanks -- Regards Frank Yu