If you look at the current pg_num in that pool ls detail command that Dan mentioned you can set the pool pg_num to what that value currently is, which will effectively pause the pg changes. I did this recently when decreasing the number of pg's in a pool, which took several weeks to complete. This let me get some other maintenance done before setting the pg_num back to the target num again. This works well for reduction, but I'm not sure if it works well for increase as I think the pg_num may reach the target much faster and then just the pgp_num changes till they match. Rich On Wed, 22 Sept 2021 at 23:06, Dan van der Ster <dan@xxxxxxxxxxxxxx> wrote: > > To get an idea how much work is left, take a look at `ceph osd pool ls > detail`. There should be pg_num_target... The osds will merge or split PGs > until pg_num matches that value. > > .. Dan > > > On Wed, 22 Sep 2021, 11:04 Jan-Philipp Litza, <jpl@xxxxxxxxx> wrote: > > > Hi everyone, > > > > I had the autoscale_mode set to "on" and the autoscaler went to work and > > started adjusting the number of PGs in that pool. Since this implies a > > huge shift in data, the reweights that the balancer had carefully > > adjusted (in crush-compat mode) are now rubbish, and more and more OSDs > > become nearful (we sadly have very different sized OSDs). > > > > Now apparently both manager modules, balancer and pg_autoscaler, have > > the same threshold for operation, namely target_max_misplaced_ratio. So > > the balancer won't become active as long as the pg_autoscaler is still > > adjusting the number of PGs. > > > > I already set the autoscale_mode to "warn" on all pools, but apparently > > the autoscaler is determined to finish what it started. > > > > Is there any way to pause the autoscaler so the balancer has a chance of > > fixing the reweights? Because even in manual mode (ceph balancer > > optimize), the balancer won't compute a plan when the misplaced ratio is > > higher than target_max_misplaced_ratio. > > > > I know about "ceph osd reweight-*", but they adjust the reweights > > (visible in "ceph osd tree"), whereas the balancer adjusts the "compat > > weight-set", which I don't know how to convert back to the old-style > > reweights. > > > > Best regards, > > Jan-Philipp > > _______________________________________________ > > 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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