Hi! > 2. One node (with 8 osds) goes offline. Will ceph automatically replicate all > objects on the remaining node to maintain number of replicas = 2? > No, because it can no longer satisfy your CRUSH rules. Your crush rule states > 1x copy pr. node and it will keep it that way. The cluster will go into a > degraded state until you can bring up another node (ie all your data now is > very vulnerable). I think it is often suggested to run with 3x replica if > possible - or at the very least nr_nodes = replicas + 1. If you had to make > it replicate on the remaining node you'd have to change your CRUSH rule to > replicate based on OSD and not node. But then you'll most likely have > problems when 1 node dies because objects could easily be on 2x OSD on the > failed node.
Is it possible to define "fallback" crush rule, which must work if main rule cannot obtain needed number of replicas? Pavel. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
