[ceph-users] HEALTH_WARN 1 pools have too few placement groups

Hi, I was planing to activate the pg_autoscaler on a EC (6+3) pool which I created two years ago. Back then I calculated the total # of pgs for this pool with a target per ods pg # of 150 (this was the recommended /osd pg number as far as I recall). I used the RedHat ceph pg per pool calculator [1] with the following settings: PoolyType: EC K: 6 M: 3 OSD #: 220 %Data: 100.00 Target PGs per OSD: 150 This resulted into a suggested PG count of 4096, which I used to create that pool. (BTW: I get the same using the ceph.io pgcalc [2], setting size to 9 (=EC 6+3)) # ceph osd df shows that I have now 162-169 pgs / osd Now I enabled the pg_autoscaler and set autoscale_mode to "warn", using the following commands: # ceph mgr module enable pg_autoscaler # ceph osd pool set hdd-ec-data-pool pg_autoscale_mode warn when i set the target_ratio_size to 1, using: # ceph osd pool set hdd-ec-data-pool target_size_ratio 1 I get the warning: 1 pools have too few placement groups The autoscale status shows that pg number in the EC pool would get scaled up to 16384 pgs: # ceph osd pool autoscale-status POOL SIZE TARGET SIZE RATE RAW CAPACITY RATIO TARGET RATIO BIAS PG_NUM NEW PG_NUM AUTOSCALE ssd-rep-metadata-pool 11146M 3.0 29805G 0.0011 1.0 64 4 off ssd-rep-data-pool 837.8G 3.0 29805G 0.0843 1.0 1024 64 off hdd-ec-data-pool 391.3T 1.5 1614T 0.3636 1.0000 1.0 4096 16384 warn How does this relate the the calculated number of 4096 pgs for that EC pool? I mean 16384 is quite a jump from the original value. Is the autoscaler miscalculating something or is the pg calculator wrong? Can someone explain it? (My cluster is on ceph version 14.2.7) Thanks so much Dietmar [1]: https://access.redhat.com/labs/cephpgc/ [2]: https://ceph.io/pgcalc/ -- _________________________________________ D i e t m a r R i e d e r, Mag.Dr. Innsbruck Medical University Biocenter - Institute of Bioinformatics Innrain 80, 6020 Innsbruck Email: dietmar.rieder(a)i-med.ac.at Web: http://www.icbi.at