Good evening! The following problem occurred. There is a cluster ceph 16.2.10 The cluster was operating normally on Friday. Shut down cluster: -Excluded all clients Executed commands: ceph osd set noout ceph osd set nobackfill ceph osd set norecover ceph osd set norebalance ceph osd set nodown ceph osd set pause Turned off the cluster, checked server maintenance. Enabled cluster. He gathered himself, found all the nodes, and here the problem began. After all OSD went up and all pg became available, cephfs refused to start. Now mds are in the replay status, and do not go to the ready status. Previously, one of them was in the replay (laggy) status, but we executed command: ceph config set mds mds_wipe_sessions true After that, mds switched to the status of replays, the third in standby status started, and mds crashes with an error stopped. But cephfs is still unavailable. What else can we do? The cluster is very large, almost 200 million files. Best regards A.Tsivinsky e-mail: alexey.tsivinsky@baikalelectronics.com