Hey, I'm running ceph version 18.2.1 (reef) but this problem must have existed a long time before reef. The documentation says the autoscaler will target 100 pgs per OSD but I'm only seeing ~10. My erasure encoding is a stripe of 6 data 3 parity. Could that be the reason? PGs numbers for that EC pool are therefore multiplied by k+m by the autoscaler calculations? Is backfill_toofull calculated against the total size of the PG against every OSD it is destined for? For my case I have ~1TiB PGs because the autoscaler is creating only 10 per host, and then backfill too full is considering that one of my OSDs only has 500GiB free, although that doesn't quite add up either because two 1TiB PGs are backfilling two pg's that have OSD 1 in them. My backfill full ratio is set to 97%. Would it be correct for me to change the autoscaler to target ~700 pgs per osd and bias for storagefs and all EC pools to k+m? Should that be the default or the documentation recommended value? How scary is changing PG_NUM while backfilling misplaced PGs? It seems like there's a chance the backfill might succeed so I think I can wait. Any help is greatly appreciated, I've tried to include as much of the relevant debugging output as I can think of. Daniel # ceph osd ls | wc -l 44 # ceph pg ls | wc -l 484 # ceph osd pool autoscale-status POOL SIZE TARGET SIZE RATE RAW CAPACITY RATIO TARGET RATIO EFFECTIVE RATIO BIAS PG_NUM NEW PG_NUM AUTOSCALE BULK .rgw.root 216.0k 3.0 480.2T 0.0000 1.0 32 on False default.rgw.control 0 3.0 480.2T 0.0000 1.0 32 on False default.rgw.meta 0 3.0 480.2T 0.0000 1.0 32 on False default.rgw.log 1636k 3.0 480.2T 0.0000 1.0 32 on False storagefs 233.5T 1.5 480.2T 0.7294 1.0 256 on False storagefs-meta 850.2M 4.0 480.2T 0.0000 4.0 32 on False storagefs_wide 355.3G 1.375 480.2T 0.0010 1.0 32 on False .mgr 457.3M 3.0 480.2T 0.0000 1.0 1 on False mgr-backup-2022-08-19 370.6M 3.0 480.2T 0.0000 1.0 32 on False # ceph osd pool ls detail | column -t pool 15 '.rgw.root' replicated size 3 min_size 2 crush_rule 0 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on pool 16 'default.rgw.control' replicated size 3 min_size 2 crush_rule 0 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on pool 17 'default.rgw.meta' replicated size 3 min_size 2 crush_rule 0 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on pool 18 'default.rgw.log' replicated size 3 min_size 2 crush_rule 0 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on pool 36 'storagefs' erasure profile 6.3 size 9 min_size 7 crush_rule 2 object_hash rjenkins pg_num 256 pgp_num 256 autoscale_mode on pool 37 'storagefs-meta' replicated size 4 min_size 1 crush_rule 0 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on pool 45 'storagefs_wide' erasure profile 8.3 size 11 min_size 9 crush_rule 8 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on pool 46 '.mgr' replicated size 3 min_size 2 crush_rule 0 object_hash rjenkins pg_num 1 pgp_num 1 autoscale_mode on pool 48 'mgr-backup-2022-08-19' replicated size 3 min_size 2 crush_rule 0 object_hash rjenkins pg_num 32 pgp_num 32 autoscale_mode on # ceph osd erasure-code-profile get 6.3 crush-device-class= crush-failure-domain=host crush-root=default jerasure-per-chunk-alignment=false k=6 m=3 plugin=jerasure technique=reed_sol_van w=8 # ceph pg ls | awk 'NR==1 || /backfill_toofull/' | awk '{print $1" "$2" "$4" "$6" "$11" "$15" "$16}' | column -t PG OBJECTS MISPLACED BYTES STATE UP ACTING 36.f 222077 141392 953817797727 active+remapped+backfill_toofull [1,27,41,8,36,17,14,40,32]p1 [33,32,29,23,16,17,28,1,14]p33 36.5c 221761 147015 950692130045 active+remapped+backfill_toofull [26,27,40,29,1,37,39,11,42]p26 [12,24,4,2,31,25,17,33,8]p12 36.60 222710 0 957109050809 active+remapped+backfill_toofull [41,34,22,3,1,35,9,39,29]p41 [2,34,22,3,27,32,28,24,1]p2 36.6b 222202 427168 953843892012 active+remapped+backfill_toofull [20,15,7,21,37,1,38,17,32]p20 [7,2,32,26,5,35,24,17,23]p7 36.74 222681 777546 957679960067 active+remapped+backfill_toofull [42,24,12,34,38,10,27,1,25]p42 [34,33,12,0,19,14,17,30,25]p34 36.7b 222974 1560818 957691042940 active+remapped+backfill_toofull [2,35,27,1,20,18,19,12,8]p2 [31,23,21,24,35,18,19,33,25]p31 36.82 222362 1998670 954507657022 active+remapped+backfill_toofull [37,22,1,38,11,23,27,32,33]p37 [27,33,0,32,5,25,20,13,15]p27 36.b5 221676 1330056 953443725830 active+remapped+backfill_toofull [6,8,38,12,21,1,39,34,27]p6 [33,8,26,12,3,10,22,34,1]p33 36.b6 222669 1335327 956973704883 active+remapped+backfill_toofull [11,13,41,4,12,34,29,6,1]p11 [2,29,34,4,12,9,15,6,28]p2 36.e0 221518 1772144 952581426388 active+remapped+backfill_toofull [1,27,21,31,30,23,37,13,28]p1 [25,21,14,31,1,2,34,17,24]p25 ceph pg ls | awk 'NR==1 || /backfilling/' | grep -e BYTES -e '\[1' -e ',1,' -e '1\]' | awk '{print $1" "$2" "$4" "$6" "$11" "$15" "$16}' | column -t PG OBJECTS MISPLACED BYTES STATE UP ACTING 36.4a 221508 89144 951346455917 active+remapped+backfilling [40,43,33,32,30,38,22,35,9]p40 [27,10,20,7,30,21,1,28,31]p27 36.79 222315 1111575 955797107713 active+remapped+backfilling [1,36,31,33,25,23,14,3,13]p1 [27,6,31,23,25,5,14,29,13]p27 36.8d 222229 1284156 955234423342 active+remapped+backfilling [35,34,27,37,38,36,43,3,16]p35 [35,34,15,26,1,11,27,18,16]p35 36.ba 222039 0 952547107971 active+remapped+backfilling [0,40,33,23,41,4,27,22,28]p0 [0,35,33,27,1,3,30,22,28]p0 36.da 221607 277464 951599928383 active+remapped+backfilling [21,31,8,9,11,25,36,23,28]p21 [0,10,1,22,33,11,35,15,28]p0 36.db 221685 58816 951420054091 active+remapped+backfilling [3,28,12,13,1,38,40,35,43]p3 [27,20,17,21,1,23,28,24,31]p27 # ceph osd df | sort -nk 17 | tail -n 5 21 hdd 9.09598 1.00000 9.1 TiB 7.7 TiB 7.7 TiB 0 B 31 GiB 1.4 TiB 84.62 1.16 68 up 24 hdd 9.09598 1.00000 9.1 TiB 7.7 TiB 7.7 TiB 1 KiB 25 GiB 1.4 TiB 84.98 1.16 69 up 29 hdd 9.09569 1.00000 9.1 TiB 8.0 TiB 8.0 TiB 72 MiB 23 GiB 1.1 TiB 88.42 1.21 73 up 13 hdd 9.09569 1.00000 9.1 TiB 8.1 TiB 8.1 TiB 1 KiB 22 GiB 1023 GiB 89.02 1.22 76 up 1 hdd 7.27698 1.00000 7.3 TiB 6.8 TiB 6.8 TiB 27 MiB 18 GiB 451 GiB 93.94 1.28 64 up # cat /etc/ceph/ceph.conf | grep full mon_osd_full_ratio = .98 mon_osd_nearfull_ratio = .96 mon_osd_backfillfull_ratio = .97 osd_backfill_full_ratio = .97 osd_failsafe_full_ratio = .99