On 6/4/20 12:24 AM, Frank Schilder wrote: > You can use the command-line without editing the crush map. Look at the documentation of commands like > > ceph osd crush add-bucket ... > ceph osd crush move ... > > Before starting this, set "ceph osd set norebalance" and unset after you are happy with the crush tree. Let everything peer. You should see misplaced objects and remapped PGs, but no degraded objects or PGs. > > Do this only when cluster is helth_ok, otherwise things can get really complicated. > Yes and No. This will cause many CRUSHMap updates where a manual update is only a single change. I would do: $ ceph osd getcrushmap -o crushmap $ cp crushmap crushmap.backup $ crushtool -d crushmap -o crushmap.txt $ vi crushmap.txt (now make your changes) $ crushtool -c crushmap.txt -o crushmap.new $ crushtool -i crushmap.new --tree (check if all OK) $ crushtool -i crushmap.new --test --rule 0 --num-rep 3 --show-mappings If all is good: $ ceph osd setcrushmap -i crushmap.new If all goes bad, simply revert to your old crushmap. Wido > Best regards, > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > > ________________________________________ > From: Kyriazis, George <george.kyriazis@xxxxxxxxx> > Sent: 03 June 2020 22:45:11 > To: ceph-users > Subject: Best way to change bucket hierarchy > > Helo, > > I have a live ceph cluster, and I’m in the need of modifying the bucket hierarchy. I am currently using the default crush rule (ie. keep each replica on a different host). My need is to add a “chassis” level, and keep replicas on a per-chassis level. > > From what I read in the documentation, I would have to edit the crush file manually, however this sounds kinda scary for a live cluster. > > Are there any “best known methods” to achieve that goal without messing things up? > > In my current scenario, I have one host per chassis, and planning on later adding nodes where there would be >1 hosts per chassis. It looks like “in theory” there wouldn’t be a need for any data movement after the crush map changes. Will reality match theory? Anything else I need to watch out for? > > Thank you! > > George > > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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