Hi Ray, Disabling the autoscaler on all pools is probably a good idea. At least until https://tracker.ceph.com/issues/53729 is fixed. (You are likely not susceptible to that -- but better safe than sorry).
To pause the ongoing PG merges, you can indeed set the pg_num to the current value. This will allow the ongoing merge complete and prevent further merges from starting. >From `ceph osd pool ls detail` you'll see pg_num, pgp_num, pg_num_target, pgp_num_target... If you share the current values of those we can help advise what you need to set the pg_num to to effectively pause things where they are. BTW -- I'm going to create a request in the tracker that we improve the pg autoscaler heuristic. IMHO the autoscaler should estimate the time to carry out a split/merge operation and avoid taking one-way decisions without permission from the administrator. The autoscaler is meant to be helpful, not degrade a cluster for 100 days! Cheers, Dan On Tue, Apr 12, 2022 at 9:04 PM Ray Cunningham <ray.cunning...@keepertech.com> wrote: > > Hi Everyone, > > We just upgraded our 640 OSD cluster to Ceph 16.2.7 and the resulting > rebalancing of misplaced objects is overwhelming the cluster and impacting > MON DB compaction, deep scrub repairs and us upgrading legacy bluestore OSDs. > We have to pause the rebalancing if misplaced objects or we're going to fall > over. > > Autoscaler-status tells us that we are reducing our PGs by 700'ish which will > take us over 100 days to complete at our current recovery speed. We disabled > autoscaler on our biggest pool, but I'm concerned that it's already on the > path to the lower PG count and won't stop adding to our misplaced count after > drop below 5%. What can we do to stop the cluster from finding more misplaced > objects to rebalance? Should we set the PG num manually to what our current > count is? Or will that cause even more havoc? > > Any other thoughts or ideas? My goals are to stop the rebalancing temporarily > so we can deep scrub and repair inconsistencies, upgrade legacy bluestore > OSDs and compact our MON DBs (supposedly MON DBs don't compact when you > aren't 100% active+clean). > > Thank you, > Ray > > _______________________________________________ > ceph-users mailing list -- ceph-users@ceph.io > To unsubscribe send an email to ceph-users-le...@ceph.io _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
