Dan; I don't have a lot of experience with Ceph, but I generally set all of the following before taking a cluster offline: ceph osd set noout ceph osd set nobackfill ceph osd set norecover ceph osd set norebalance ceph osd set nodown ceph osd set pause I then unset them in the opposite order: ceph osd unset pause ceph osd unset nodown ceph osd unset norebalance ceph osd unset norecover ceph osd unset nobackfill ceph osd unset noout This may be overkill though. Will the MONs still have a quorum (i.e. will n / 2 + 1 still be running)? Thank you, Dominic L. Hilsbos, MBA Director - Information Technology Perform Air International Inc. DHilsbos@xxxxxxxxxxxxxx www.PerformAir.com -----Original Message----- From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of Dan van der Ster Sent: Thursday, July 25, 2019 7:48 AM To: ceph-users Subject: how to power off a cephfs cluster cleanly Hi all, In September we'll need to power down a CephFS cluster (currently mimic) for a several-hour electrical intervention. Having never done this before, I thought I'd check with the list. Here's our planned procedure: 1. umounts /cephfs from all hpc clients. 2. ceph osd set noout 3. wait until there is zero IO on the cluster 4. stop all mds's (active + standby) 5. stop all osds. (6. we won't stop all mon's as they are not affected by that electrical intervention) 7. power off the cluster. ... 8. power on the cluster, osd's first, then mds's. wait for health_ok. 9. ceph osd unset noout Seems pretty simple... Are there any gotchas I'm missing? Maybe there's some special procedure to stop the mds's cleanly? Cheers, dan _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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