Quoting James Wilkins (james.wilkins@xxxxxxxxxxxxx): > Hi all, > > Just want to (double) check something – we’re in the process of > luminous -> mimic upgrades for all of our clusters – particularly this > section regarding MDS steps > > • Confirm that only one MDS is online and is rank 0 for your FS: # > ceph status • Upgrade the last remaining MDS daemon by installing > the new packages and restarting the daemon: > > Namely – is it required to upgrade the live single MDS in place (and > thus have downtime whilst the MDS restarts – on our first cluster was > typically 10 minutes of downtime ) – or can we upgrade the > standby-replays/standbys first and flip once they are back? You should upgrade in place (the last remaining MDS) and yes that causes a bit of downtime. In our case it takes ~ 5s. Make sure to _only_ upgrade the ceph packages (no apt upgrade of whole system) as apt will happily disable services, start updating initramfs ... for all installed kernels, etc. Doing the full upgrade and reboot can be done later. This is how we do it: On (Active) Standby: mds2: systemctl stop ceph-mds.target On Active: apt update apt policy ceph-base <- check that the version that is available is indeed the version you want to upgrade to! apt install ceph-base ceph-common ceph-fuse ceph-mds ceph-mds-dbg libcephfs2 python-cephfs If mds doesn't get restarted with the upgrade, do it manually: systemctl restart ceph-mds.target ^^ a bit of downtime ceph daemon mds.$id version <- to make sure you are running the upgraded version (or run ceph versions to check) On Standby: apt install ceph-base ceph-common ceph-fuse ceph-mds ceph-mds-dbg libcephfs2 python-cephfs systemctl restart ceph-mds.target ceph daemon mds.$id version <- to make sure you are running the upgraded version On Active: apt upgrade && reboot (Standby becomes active) wait for HEALTH_OK On (now) Active (previously standby): apt upgrade && reboot If you follow this procedure you end up with the same active and standby as before the upgrades, both up to date with as little downtime as possible. That said ... I've accidentally updated a standby MDS to a newer version than the Active one ... and this didn't cause any issues (12.2.8 -> 12.2.11) ... but I would not recommend it. Gr. Stefan -- | BIT BV http://www.bit.nl/ Kamer van Koophandel 09090351 | GPG: 0xD14839C6 +31 318 648 688 / info@xxxxxx _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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