How to remove/add OSD from Ceph cluster
Remove OSD from Ceph Cluster Firstly check which OSD is down and want to remove from Ceph Cluster by using given command: ceph osd tree . Let’s say it is osd.20 which is down and want to remove. Now use the following commands a. ceph osd out osd.20 ( If you see “ osd.20 is already out ” — it’s ok. ) b. ceph osd down osd.20 c. Remove it: ceph osd rm osd.20 If it says ‘ Error EBUSY: osd.11 is still up; must be down before removal. ’ that means OSD is not dead yet. Go to the host it resides on and kill it ( systemctl stop ceph-osd@20 ), and repeat rm operation. d. ceph osd crush rm osd.20 e. remove it authorization (it should prevent problems with ‘couldn’t add new osd with same number’): ceph auth del osd.20 . f. Make sure it is safe to destroy the OSD: ceph osd destroy 20 --yes-i-really-mean-it g. Now check with the following command: ceph -s or ceph -w h. If want to remove ceph LVM volume created on host m...