Exactly. Use the orchestrator, Luke. Additionally I would set count:3 for the mgr service. It’s kind of a hassle to recover from no active mgr so I encourage running one alongside every mon.
> On Jul 21, 2026, at 4:30 PM, Eugen Block via ceph-users <[email protected]> > wrote: > > Hi, > > Ceph is highly-available by design. So if you have three MON nodes (and two > MGR services deployed along them) you're good as long as you have quorum and > an admin keyring on more than one node. With cephadm you can manage the > presence of the admin keyring via orchestrator and the _admin label [0]. That > enables you to manage the cluster from any admin node. Not sure what you mean > by "bootstrap file" though... > > If you'd synced the /var/lib/ceph directory, you'd overwrite all the daemons > but one, including keyring etc. So please don't do that, that would break > your cluster. > > Regards, > Eugen > > [0] > https://docs.ceph.com/en/latest/cephadm/operations/#enabling-management-of-a-keyring-file > > Zitat von Michel Le Cocq via ceph-users <[email protected]>: > >> Hi all, >> >> I am currently deploying a Ceph cluster with cephadm on 3 nodes with >> MON, MGR, and MDS roles. OSDs will be added later. >> >> My goal is for these 3 nodes to be fully interchangeable, with the >> ability to administer the cluster from any of them without risk if a >> node fails. >> >> I have identified that the solution involves synchronizing >> /var/lib/ceph/ (excluding the bootstrap file) across all nodes. >> >> However: >> >> - Is this the right approach to achieve this goal? >> >> - Which tool should I use for reliable bidirectional synchronization? >> >> - What are the potential risks (conflicts, corruption) and precautions >> to take? >> >> Have you implemented such a configuration in production before? >> >> Thank you for your advice. >> >> -- >> Michel >> _______________________________________________ >> ceph-users mailing list -- [email protected] >> To unsubscribe send an email to [email protected] > > > _______________________________________________ > ceph-users mailing list -- [email protected] > To unsubscribe send an email to [email protected] _______________________________________________ ceph-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
