Hi! I have a nautilus ceph cluster, and today I restarted one of the osd daemons and spend some time trying to debug an error I was seeing in the log, though it seems the osd is actually working. The error I was seeing is: ``` Nov 25 09:07:43 osd15 systemd[1]: Starting Ceph object storage daemon osd.44... Nov 25 09:07:43 osd15 systemd[1]: Started Ceph object storage daemon osd.44. Nov 25 09:07:47 osd15 ceph-osd[12230]: 2020-11-25 09:07:47.846 7f55395fbc80 -1 osd.44 106947 log_to_monitors {default=true} Nov 25 09:07:47 osd15 ceph-osd[12230]: 2020-11-25 09:07:47.850 7f55395fbc80 -1 osd.44 106947 mon_cmd_maybe_osd_create fail: 'osd.44 has already bound to class 'ssd', can not reset class to 'hdd'; use 'ceph osd crush rm-device-class <id>' to remove old class first': (16) Device or resource busy ``` There's no other messages in the journal so at first I thought that the osd failed to start. But it seems to be up and working correctly anyhow. There's no "hdd" class in my crush map: ``` # ceph osd crush class ls [ "ssd" ] ``` And that osd is actually of the correct class: ``` # ceph osd crush get-device-class osd.44 ssd ``` ``` # uname -a Linux osd15 4.19.0-9-amd64 #1 SMP Debian 4.19.118-2+deb10u1 (2020-06-07) x86_64 GNU/Linux # ceph --version ceph version 14.2.5-1-g23e76c7aa6 (23e76c7aa6e15817ffb6741aafbc95ca99f24cbb) nautilus (stable) ``` The osd shows up in the cluster and it's receiving load, so there seems to be no problem, but does anyone know what that error is about? Thanks! -- David Caro SRE - Cloud Services Wikimedia Foundation <https://wikimediafoundation.org/> PGP Signature: 7180 83A2 AC8B 314F B4CE 1171 4071 C7E1 D262 69C3 "Imagine a world in which every single human being can freely share in the sum of all knowledge. That's our commitment."