Stop clients
Then:
ceph osd set noout ceph osd set nobackfill ceph osd set norecover
Those flags should be totally sufficient to safely powerdown your cluster but you could also set the following flags on top if you would like to pause your cluster completely::
ceph osd set norebalance ceph osd set nodown ceph osd set pause
Pausing the cluster means that you can't see when OSDs come back up again and no map update will happen
Then:
- shutdown rados-gw
- shutdown osd
- shutdown mons
After maintenance just do everything mentioned above in reverse order.