Hi guys, I'm testing Ceph Pacific 16.2.4 in my lab before deciding if I will put it in production on a 1PB+ storage cluster with rgw-only access. I noticed a weird issue with my mons : - if I reboot a mon host, the ceph-mon container is not starting after reboot - I can see with 'ceph orch ps' the following output : mon.node01 node01 running (20h) 4m ago 20h 16.2.4 8d91d370c2b8 0a2e86af94b2 mon.node02 node02 running (115m) 12s ago 115m 16.2.4 8d91d370c2b8 51f4885a1b06 mon.node03 node03 stopped 4m ago 19h <unknown> <unknown> <unknown> (where node03 is the host which was rebooted). - I tried to start the mon container manually on node03 with '/bin/bash /var/lib/ceph/c2d41ac4-baf5-11eb-865d-2dc838a337a3/mon.node03/unit.run' and I've got the following output : debug 2021-05-23T08:24:25.192+0000 7f9a9e358700 0 mon.node03@-1(???).osd e408 crush map has features 3314933069573799936, adjusting msgr requires debug 2021-05-23T08:24:25.192+0000 7f9a9e358700 0 mon.node03@-1(???).osd e408 crush map has features 432629308056666112, adjusting msgr requires debug 2021-05-23T08:24:25.192+0000 7f9a9e358700 0 mon.node03@-1(???).osd e408 crush map has features 432629308056666112, adjusting msgr requires debug 2021-05-23T08:24:25.192+0000 7f9a9e358700 0 mon.node03@-1(???).osd e408 crush map has features 432629308056666112, adjusting msgr requires cluster 2021-05-23T08:07:12.189243+0000 mgr.node01.ksitls (mgr.14164) 36380 : cluster [DBG] pgmap v36392: 417 pgs: 417 active+clean; 33 KiB data, 605 MiB used, 651 GiB / 652 GiB avail; 9.6 KiB/s rd, 0 B/s wr, 15 op/s debug 2021-05-23T08:24:25.196+0000 7f9a9e358700 1 mon.node03@-1(???).paxosservice(auth 1..51) refresh upgraded, format 0 -> 3 debug 2021-05-23T08:24:25.208+0000 7f9a88176700 1 heartbeat_map reset_timeout 'Monitor::cpu_tp thread 0x7f9a88176700' had timed out after 0.000000000s debug 2021-05-23T08:24:25.208+0000 7f9a9e358700 0 mon.node03@-1(probing) e5 my rank is now 1 (was -1) debug 2021-05-23T08:24:25.212+0000 7f9a87975700 0 mon.node03@1(probing) e6 removed from monmap, suicide. root@node03:/home/adrian# systemctl status ceph-c2d41ac4-baf5-11eb-865d-2dc838a337a3@mon.node03.service ● ceph-c2d41ac4-baf5-11eb-865d-2dc838a337a3@mon.node03.service - Ceph mon.node03 for c2d41ac4-baf5-11eb-865d-2dc838a337a3 Loaded: loaded (/etc/systemd/system/ceph-c2d41ac4-baf5-11eb-865d-2dc838a337a3@.service; enabled; vendor preset: enabled) Active: inactive (dead) since Sun 2021-05-23 08:10:00 UTC; 16min ago Process: 1176 ExecStart=/bin/bash /var/lib/ceph/c2d41ac4-baf5-11eb-865d-2dc838a337a3/mon.node03/unit.run (code=exited, status=0/SUCCESS) Process: 1855 ExecStop=/usr/bin/docker stop ceph-c2d41ac4-baf5-11eb-865d-2dc838a337a3-mon.node03 (code=exited, status=1/FAILURE) Process: 1861 ExecStopPost=/bin/bash /var/lib/ceph/c2d41ac4-baf5-11eb-865d-2dc838a337a3/mon.node03/unit.poststop (code=exited, status=0/SUCCESS) Main PID: 1176 (code=exited, status=0/SUCCESS) The only fix I could find was to redeploy the mon with : ceph orch daemon rm mon.node03 --force ceph orch daemon add mon node03 However, even if it's working after redeploy, it's not giving me a lot of trust to use it in a production environment having an issue like that. I could reproduce it with 2 different mons so it's not just an exception. My setup is based on Ubuntu 20.04 and docker instead of podman : root@node01:~# docker -v Docker version 20.10.6, build 370c289 Do you know a workaround for this issue or is this a known bug ? I noticed that there are some other complaints with the same behaviour in Octopus as well and the solution at that time was to delete the /var/lib/ceph/mon folder . Thanks.