On Thu, Jan 5, 2017 at 7:24 AM, Klemen Pogacnik <klemen@xxxxxxxxxx> wrote: > I'm playing with rbd mirroring with openstack. The final idea is to use it > for disaster recovery of DB server running on Openstack cluster, but would > like to test this functionality first. > I've prepared this configuration: > - 2 openstack clusters (devstacks) > - 2 ceph clusters (one node clusters) > Remote Ceph is used as a backend for Cinder service. Each devstack has its > own Ceph cluster. Mirroring was enabled for volumes pool, and rbd-mirror > daemon was started. > When I create new cinder volume on devstack1, the same rbd storage appeared > on both Ceph clusters, so it seems, mirroring is working. > Now I would like to see this storage as a Cinder volume on devstack2 too. Is > it somehow possible to do that? This level is HA/DR is not currently built-in to OpenStack (it's outside the scope of Ceph). There are several strategies you could use to try to replicate the devstack1 database to devstack2. Here is a presentation from OpenStack Summit Austin [1] re: this subject. > The next question is, how to make switchover. On Ceph it can easily be done > by demote and promote commands, but then the volumes are still not seen on > Devstack2, so I can't use it. > On open stack there is cinder failover-host command, which is, as I can > understand, only useful for configuration with one openstack and two ceph > clusters. Any idea how to make switchover with my configuration. > Thanks a lot for help! Correct -- Cinder's built-in volume replication feature is just a set of hooks available for backends that already support replication/mirroring. The hooks for Ceph RBD are scheduled to be included in the next release of OpenStack, but as you have discovered, it really only protects against a storage failure (where you can switch from Ceph cluster A to Ceph cluster B), but does not help with losing your OpenStack data center. > Kemo > > > > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > [1] https://www.openstack.org/videos/video/protecting-the-galaxy-multi-region-disaster-recovery-with-openstack-and-ceph -- Jason _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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