OK -- here's the tracker for what I mentioned: https://tracker.ceph.com/issues/55303 On Tue, Apr 12, 2022 at 9:50 PM Ray Cunningham <ray.cunningham@xxxxxxxxxxxxxx> wrote: > > Thank you Dan! I will definitely disable autoscaler on the rest of our pools. I can't get the PG numbers today, but I will try to get them tomorrow. We definitely want to get this under control. > > Thank you, > Ray > > > -----Original Message----- > From: Dan van der Ster <dvanders@xxxxxxxxx> > Sent: Tuesday, April 12, 2022 2:46 PM > To: Ray Cunningham <ray.cunningham@xxxxxxxxxxxxxx> > Cc: ceph-users@xxxxxxx > Subject: Re: Stop Rebalancing > > 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.cunningham@xxxxxxxxxxxxxx> 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@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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