Many thank to those who have responded! Will comment on everything in this message, for brevity. On 2026-04-14 17:00, Eugen Block via ceph-users wrote:

First thing coming to mind is: ceph mgr fail

If you already did that something else is going on.

you write "all the daemons which should be up and running ARE up and running. In particular, all the expected OSDs appear to be operational". Does that mean, that not all OSDs are running? No, all OSDs are expected to be running at present so what I meant by

I have indeed already tried it, several times in fact. Seems to have no effect. On 2026-04-14 17:41, tobias tempel wrote: the above was that all were - indeed, still are - up. Should have made it more clear, apologies. On 2026-04-14 18:05, Malte Stroem wrote:

add storage to the cluster.

Is this expected to help if the cluster is nowhere near full? According to 'ceph osd df' even the most heavily utilised OSDs are only about 20% full, and most of them are half that or less.

Please show us:

ceph -s

As of a few minutes ago, this shows: cluster: id: (REDACTED) health: HEALTH_OK services: mon: 5 daemons, quorum cdev01,cdev02,cdev03,cdev06,cdev08(age 3d) [leader: cdev01] mgr: cdev04.lmasuw(active, since 2d), standbys: cdev01.dgatgl, cdev08.nxaiqd mds: 1/1 daemons up, 2 standby osd: 88 osds: 88 up (since 2d), 88 in (since 9w); 1448 remapped pgs rgw: 6 daemons active (3 hosts, 1 zones) data: volumes: 1/1 healthy pools: 13 pools, 2641 pgs objects: 98.57M objects, 27 TiB usage: 105 TiB used, 846 TiB / 951 TiB avail pgs: 76576200/314890284 objects misplaced (24.318%) 1448 active+clean+remapped 1189 active+clean 2 active+clean+scrubbing+deep 2 active+clean+scrubbing io: client: 986 KiB/s rd, 0 B/s wr, 120 op/s rd, 0 op/s wr Nb. The number of misplaced objects HAS in fact decreased slightly (by about 0.3%) since two days ago so something IS happening, if extremely slowly. -- MS