Hi, basically it's that easy [0] when only one or few hosts are reinstalled but the cluster is otherwise operative: ceph cephadm osd activate <host>... If your cluster has lost all monitors, it can get difficult. You can rebuild the mon store [1] by collecting required information from *ALL* OSDs. But some keyrings won't be there [2], so I recommend to dump your auth keys regularly and store them in your backup. If you also have one or more Ceph Filesystems, and the mds map would be lost in case of a total mon store failure, you would need to create a new CephFS with the existing pools. Regards, Eugen [0] https://docs.ceph.com/en/latest/cephadm/services/osd/#activate-existing-osds [1] https://docs.ceph.com/en/latest/rados/troubleshooting/troubleshooting-mon/#r... [2] https://docs.ceph.com/en/latest/rados/troubleshooting/troubleshooting-mon/#k... Zitat von Jayant Dang <jayant.dang07@gmail.com>:
Hi Can someone help me understand what happens in a scenario if my os disk of all the ceph nodes gets destroyed somehow and I am only left with the OSDs or physical storage devices, How can I recreate the same ceph cluster using those old OSDs without any data loss ? Is there something I should regularly backup to recreate a ceph cluster ? _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io