Hi, I'm currently working on upgrading my existing monitors within my cluster. During the first deployment of this production cluster I made some choices that in hindsight where not the best. But, it worked, I learned and now I wish to mediate my previous bad choices. The cluster exists of three monitors that are currently in quorum and I wish to upgrade each of them by fully removing them from the cluster and rejoining them after a complete reinstall of the os (new hostname, new ip). Therefore I want to maintain quorum by temporary adding a monitor but this won't go as planned as the monitor will join, with `ceph-deploy add monitor mon4` but never leave the probing state (see log below). I have verified all networking and firewall settings and don't notice any connection errors, neither do I see any weird hostnames or ip-addresses in the existing monmap on all the hosts. Also manually confirmed that all the keys on the cluster are the same, so don't suspect a authentication error. Hope someone has any guidance. Thx. Log from mon4 > /var/log/ceph/ceph-mon.mon4.log 2019-10-16 11:21:51.960 7fc709c73a00 0 mon.mon4 does not exist in monmap, will attempt to join an existing cluster 2019-10-16 11:21:51.962 7fc709c73a00 0 using public_addr 10.200.1.104:0/0 -> 10.200.1.104:6789/0 2019-10-16 11:21:51.963 7fc709c73a00 0 starting mon.mon4 rank -1 at public addr 10.200.1.104:6789/0 at bind addr 10.200.1.104:6789/0 mon_data /var/lib/ceph/mon/ceph-mon4 fsid aaf1547b-8944-4f48-b354-93659202c6fe 2019-10-16 11:21:51.964 7fc709c73a00 0 starting mon.mon4 rank -1 at 10.200.1.104:6789/0 mon_data /var/lib/ceph/mon/ceph-mon4 fsid aaf1547b-8944-4f48-b354-93659202c6fe 2019-10-16 11:21:51.965 7fc709c73a00 1 mon.mon4@-1(probing) e0 preinit fsid aaf1547b-8944-4f48-b354-93659202c6fe 2019-10-16 11:21:51.965 7fc709c73a00 1 mon.mon4@-1(probing) e0 initial_members mon1,mon2,mon3,mon4, filtering seed monmap 2019-10-16 11:21:51.965 7fc709c73a00 1 mon.mon4@-1(probing).mds e0 Unable to load 'last_metadata' 2019-10-16 11:21:51.967 7fc709c73a00 0 mon.mon4@-1(probing) e0 my rank is now 3 (was -1) 2019-10-16 11:21:54.054 7fc6f934b700 0 log_channel(audit) log [DBG] : from='admin socket' entity='admin socket' cmd='mon_status' args=[]: dispatch 2019-10-16 11:21:54.054 7fc6f934b700 0 log_channel(audit) log [DBG] : from='admin socket' entity='admin socket' cmd=mon_status args=[]: finished 2019-10-16 11:21:54.300 7fc6f934b700 0 log_channel(audit) log [DBG] : from='admin socket' entity='admin socket' cmd='mon_status' args=[]: dispatch 2019-10-16 11:21:54.300 7fc6f934b700 0 log_channel(audit) log [DBG] : from='admin socket' entity='admin socket' cmd=mon_status args=[]: finished 2019-10-16 11:22:26.967 7fc6f5ad5700 -1 mon.mon4@3(probing) e0 get_health_metrics reporting 4 slow ops, oldest is log(1 entries from seq 1 at 2019-10-16 11:21:54.055387) 2019-10-16 11:22:31.967 7fc6f5ad5700 -1 mon.mon4@3(probing) e0 get_health_metrics reporting 4 slow ops, oldest is log(1 entries from seq 1 at 2019-10-16 11:21:54.055387) 2019-10-16 11:22:36.967 7fc6f5ad5700 -1 mon.mon4@3(probing) e0 get_health_metrics reporting 4 slow ops, oldest is log(1 entries from seq 1 at 2019-10-16 11:21:54.055387) 2019-10-16 11:22:37.478 7fc6f934b700 0 log_channel(audit) log [DBG] : from='admin socket' entity='admin socket' cmd='mon_status' args=[]: dispatch 2019-10-16 11:22:37.478 7fc6f934b700 0 log_channel(audit) log [DBG] : from='admin socket' entity='admin socket' cmd=mon_status args=[]: finished 2019-10-16 11:22:41.968 7fc6f5ad5700 -1 mon.mon4@3(probing) e0 get_health_metrics reporting 4 slow ops, oldest is log(1 entries from seq 1 at 2019-10-16 11:21:54.055387) 2019-10-16 11:22:46.968 7fc6f5ad5700 -1 mon.mon4@3(probing) e0 get_health_metrics reporting 4 slow ops, oldest is log(1 entries from seq 1 at 2019-10-16 11:21:54.055387)