Comment 9 for bug 1384341

Same issue on bionic/queens.

I've added new addresses to all units, and run:
juju config ceph-osd ceph-public-network=172.16.1.0/24 ceph-cluster-network=172.16.1.0/24
juju config ceph-mon ceph-public-network=172.16.1.0/24 ceph-cluster-network=172.16.1.0/24

The new addresses appear in ceph.conf under public network, cluster network, public addr and cluster addr, and the local IP for the 'mon host' is updated, but the remaining mons (or none if on an OSD host) are not updated. Restarting ceph-mon does not change the address it listens on.

Further, https://docs.ceph.com/docs/master/rados/operations/add-or-rm-mons/#changing-a-monitor-s-ip-address says "Important Existing monitors are not supposed to change their IP addresses."

I guess that means the workaround for mons is to deploy new units. I suspect therefore that this is a documentation bug?

For OSDs, although the change does change ceph.conf, it doesn't restart the processes (which is actually good, as I'd want to coordinate that). Restarting the ceph-osd process, one by one, does appear to change the listener address, and the OSD comes up OK as long as other hosts have legs on both the old and new networks.

I have yet to find out the effect on Cinder, Glance, and Nova for the change. Advice would be appreciated.