It can work, but it might be necessary to modify the monmap first, since it's complaining that it has been removed from it. Are you familiar with the monmap-tool (https://docs.ceph.com/en/latest/man/8/monmaptool/)? The procedure is similar to changing a monitor's IP address the "messy way" (https://docs.ceph.com/en/latest/rados/operations/add-or-rm-mons/#changing-a-...). I also wrote a blog post how to do it with cephadm: https://heiterbiswolkig.blogs.nde.ag/2020/12/18/cephadm-changing-a-monitors-... But before changing anything, I'd inspect first what the current status is. You can get the current monmap from within the mon container (is it still there?): cephadm shell --name mon.<mon> ceph-monstore-tool /var/lib/ceph/mon/<your_mon> get monmap -- --out monmap monmaptool --print monmap You can paste the output here, if you want. Zitat von Jonas Schwab <jonas.schwab@uni-wuerzburg.de>:
I realized, I have access to a data directory of a monitor I removed just before the oopsie happened. Can I launch a ceph-mon from that? If I try just to launch ceph-mon, it commits suicide:
2025-04-10T19:32:32.174+0200 7fec628c5e00 -1 mon.mon.ceph2-01@-1(???) e29 not in monmap and have been in a quorum before; must have been removed 2025-04-10T19:32:32.174+0200 7fec628c5e00 -1 mon.mon.ceph2-01@-1(???) e29 commit suicide! 2025-04-10T19:32:32.174+0200 7fec628c5e00 -1 failed to initialize
On 2025-04-10 16:01, Jonas Schwab wrote:
Hello everyone,
I believe I accidentally nuked all monitor of my cluster (please don't ask how). Is there a way to recover from this desaster? I have a cephadm setup.
I am very grateful for all help!
Best regards, Jonas Schwab _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
-- Jonas Schwab
Research Data Management, Cluster of Excellence ct.qmat https://data.ctqmat.de | datamanagement.ct.qmat@listserv.dfn.de Email: jonas.schwab@uni-wuerzburg.de Tel: +49 931 31-84460 _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io