https://docs.ceph.com/docs/master/releases/nautilus/#nautilus-old-upgrade
- Upgrade ceph-mon's, one at a time. For each do:
- Set puppet-branches to a tag/branch containing nautilus ceph
- Do a puppet-run
- Update the ceph-packages on a ceph-mon
- apt-get install ceph-mon
- Restart the ceph-mon
- systemctl restart ceph-mon.target