Excellent summary. In short, the bootstrap process is one time only.
> On Jul 22, 2026, at 5:41 AM, Eugen Block via ceph-users <[email protected]> > wrote: > > Hi, responses inline... > > > Zitat von Michel Le Cocq via ceph-users <[email protected]>: > >> Actually, what confused me was this: >> >> cephadm bootstrap --mon-ip <my-ip> >> >> Among other things, this command: >> - Generates a new SSH key for the Ceph cluster and adds it >> to the /root/.ssh/authorized_keys file. >> - Saves a copy of the public key to the /etc/ceph/ceph.pub file. >> >> You then need to add a node. >> >> ssh-copy-id -f -i /etc/ceph/ceph.pub root@<new-host> >> >> ceph orch host add <newhost> [<ip>] [<label1> ...] >> >> I wondered where the private part of the SSH key /etc/ceph/ceph.pub was ! > > That's stored in the config-key db: > > ceph config-key get mgr/cephadm/ssh_identity_key > >> >> -- >> M >> >> Michel Le Cocq via ceph-users <[email protected]> writes: >> >>> Hi again. >>> >>> I'm answering my own question. >>> >>> It seems I read the wrong version of the doc >>> ... sic! >>> >>> It should be enough to set the “_admin” flag on all nodes: >>> >>> and that we also need to install cephadm on the nodes we >>> want to use for administration, right!? > > Not necessarily, but it can be more convenient for debugging. The > orchestrator stores a cephadm binary on each node to be able to manage them, > it is stored in /var/lib/ceph/{FSID}/cephadm.{SOME_DIGEST}. That's used to > remotely orchestrate the cluster/nodes etc. The original bootstrap node > requires a cephadm binary either installed as a package or downloaded via > curl as described in the docs to be able to bootstrap. After that you'll only > need to execute cephadm commands locally on the nodes if you're debugging > issues etc., otherwise the orchestrator will only use the file in > /var/lib/ceph. > >> _______________________________________________ >> 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]
