Hello, I'm new to Ceph and I recently inherited a 4 node cluster with 32 OSDs and about 116TB raw space, which shows low available space, which I'm trying to increase by enabling the balancer and lowering priority for the most-used OSDs. My questions are: is what I did correct with the current state of the cluster and can I do more to speed up rebalancing and will we actually make more space available this way? Some background info: Earlier this week MAX AVAIL on the cluster was 0 and it was only then that we noticed something was wrong. We removed an unused rbd image (about 3TB) and now we have a little under 1TB in available space. We are adding about 75GB per day on this cluster. [xxx@ceph02 ~]$ sudo ceph --cluster xxx df RAW STORAGE: CLASS SIZE AVAIL USED RAW USED %RAW USED hdd 116 TiB 47 TiB 69 TiB 69 TiB 59.69 TOTAL 116 TiB 47 TiB 69 TiB 69 TiB 59.69 POOLS: POOL ID PGS STORED OBJECTS USED %USED MAX AVAIL xxx-pool 1 1024 130 B 3 192 KiB 0 992 GiB yyy_data 6 128 23 TiB 12.08M 69 TiB 95.98 992 GiB yyy_metadata 7 128 5.6 GiB 2.22M 6.1 GiB 0.21 992 GiB Cluster status: [xxx@ceph02 ~]$ sudo ceph --cluster xxx -s cluster: id: 91ba1ea6-bfec-4ddb-a8b5-9faf842f22c3 health: HEALTH_WARN 1 backfillfull osd(s) 1 nearfull osd(s) 3 pool(s) backfillfull Low space hindering backfill (add storage if this doesn't resolve itself): 6 pgs backfill_toofull services: mon: 5 daemons, quorum a,b,c,d,e (age 5d) mgr: b(active, since 22h), standbys: a, c, d, e mds: registration_docs:1 {0=b=up:active} 3 up:standby osd: 32 osds: 32 up (since 19M), 32 in (since 3y); 36 remapped pgs task status: scrub status: mds.b: idle data: pools: 3 pools, 1280 pgs objects: 14.31M objects, 23 TiB usage: 70 TiB used, 47 TiB / 116 TiB avail pgs: 2587772/42925071 objects misplaced (6.029%) 1244 active+clean 17 active+remapped+backfilling 13 active+remapped+backfill_wait 4 active+remapped+backfill_toofull 2 active+remapped+backfill_wait+backfill_toofull io: client: 331 KiB/s wr, 0 op/s rd, 0 op/s wr recovery: 141 MiB/s, 65 keys/s, 84 objects/s Versions: [xxx@ceph02 ~]$ rpm -qa | grep ceph ceph-common-14.2.13-0.el7.x86_64 ceph-mds-14.2.13-0.el7.x86_64 ceph-osd-14.2.13-0.el7.x86_64 ceph-base-14.2.13-0.el7.x86_64 libcephfs2-14.2.13-0.el7.x86_64 python-ceph-argparse-14.2.13-0.el7.x86_64 ceph-selinux-14.2.13-0.el7.x86_64 ceph-mgr-14.2.13-0.el7.x86_64 ceph-14.2.13-0.el7.x86_64 python-cephfs-14.2.13-0.el7.x86_64 ceph-mon-14.2.13-0.el7.x86_64 It looks like the cluster is severely unbalanced and I guess that's expected because the balancer was set to "off" [xxx@ceph02 ~]$ sudo ceph --cluster xxx osd df ID CLASS WEIGHT REWEIGHT SIZE RAW USE DATA OMAP META AVAIL %USE VAR PGS STATUS 0 hdd 3.63869 1.00000 3.6 TiB 1.8 TiB 1.8 TiB 894 MiB 3.6 GiB 1.8 TiB 49.24 0.82 122 up 1 hdd 3.63869 1.00000 3.6 TiB 1.1 TiB 1.1 TiB 581 MiB 2.4 GiB 2.5 TiB 31.07 0.52 123 up 2 hdd 3.63869 1.00000 3.6 TiB 2.2 TiB 2.2 TiB 632 MiB 4.1 GiB 1.5 TiB 60.01 1.00 121 up 3 hdd 3.63869 1.00000 3.6 TiB 2.7 TiB 2.7 TiB 672 MiB 5.5 GiB 975 GiB 73.84 1.24 122 up 4 hdd 3.63869 0.94983 3.6 TiB 2.9 TiB 2.9 TiB 478 MiB 5.2 GiB 794 GiB 78.69 1.32 111 up 5 hdd 3.63869 1.00000 3.6 TiB 2.5 TiB 2.5 TiB 900 MiB 4.7 GiB 1.1 TiB 69.52 1.16 122 up 6 hdd 3.63869 1.00000 3.6 TiB 2.7 TiB 2.7 TiB 468 MiB 5.5 GiB 929 GiB 75.08 1.26 125 up 7 hdd 3.63869 1.00000 3.6 TiB 1.6 TiB 1.6 TiB 731 MiB 3.2 GiB 2.0 TiB 44.54 0.75 122 up 8 hdd 3.63869 1.00000 3.6 TiB 1.3 TiB 1.3 TiB 626 MiB 2.6 GiB 2.4 TiB 35.41 0.59 120 up 9 hdd 3.63869 1.00000 3.6 TiB 2.5 TiB 2.5 TiB 953 MiB 4.8 GiB 1.1 TiB 69.61 1.17 122 up 10 hdd 3.63869 1.00000 3.6 TiB 2.0 TiB 2.0 TiB 526 MiB 3.9 GiB 1.6 TiB 55.64 0.93 121 up 11 hdd 3.63869 0.94983 3.6 TiB 3.4 TiB 3.4 TiB 476 MiB 6.2 GiB 242 GiB 93.50 1.57 101 up 12 hdd 3.63869 1.00000 3.6 TiB 1.4 TiB 1.4 TiB 688 MiB 3.0 GiB 2.2 TiB 39.44 0.66 117 up 13 hdd 3.63869 1.00000 3.6 TiB 1.3 TiB 1.3 TiB 738 MiB 2.8 GiB 2.3 TiB 35.98 0.60 124 up 14 hdd 3.63869 1.00000 3.6 TiB 2.8 TiB 2.8 TiB 582 MiB 5.1 GiB 879 GiB 76.40 1.28 123 up 15 hdd 3.63869 1.00000 3.6 TiB 2.5 TiB 2.5 TiB 566 MiB 4.6 GiB 1.1 TiB 68.81 1.15 124 up 16 hdd 3.63869 1.00000 3.6 TiB 1.5 TiB 1.5 TiB 625 MiB 3.1 GiB 2.2 TiB 40.23 0.67 121 up 17 hdd 3.63869 0.94983 3.6 TiB 3.2 TiB 3.2 TiB 704 MiB 6.1 GiB 427 GiB 88.55 1.48 112 up 18 hdd 3.63869 1.00000 3.6 TiB 2.0 TiB 2.0 TiB 143 MiB 3.6 GiB 1.7 TiB 54.12 0.91 124 up 19 hdd 3.63869 1.00000 3.6 TiB 2.7 TiB 2.7 TiB 522 MiB 5.0 GiB 977 GiB 73.79 1.24 126 up 20 hdd 3.63869 1.00000 3.6 TiB 2.4 TiB 2.4 TiB 793 MiB 4.5 GiB 1.2 TiB 66.79 1.12 119 up 21 hdd 3.63869 1.00000 3.6 TiB 1.8 TiB 1.8 TiB 609 MiB 3.6 GiB 1.8 TiB 49.50 0.83 122 up 22 hdd 3.63869 1.00000 3.6 TiB 2.7 TiB 2.7 TiB 600 MiB 5.0 GiB 979 GiB 73.73 1.23 122 up 23 hdd 3.63869 1.00000 3.6 TiB 953 GiB 950 GiB 579 MiB 2.4 GiB 2.7 TiB 25.57 0.43 118 up 24 hdd 3.63869 1.00000 3.6 TiB 1.8 TiB 1.8 TiB 491 MiB 3.4 GiB 1.8 TiB 49.82 0.83 121 up 25 hdd 3.63869 1.00000 3.6 TiB 2.1 TiB 2.1 TiB 836 MiB 4.5 GiB 1.5 TiB 59.07 0.99 121 up 26 hdd 3.63869 0.94983 3.6 TiB 2.9 TiB 2.9 TiB 467 MiB 5.2 GiB 794 GiB 78.69 1.32 104 up 27 hdd 3.63869 1.00000 3.6 TiB 2.0 TiB 2.0 TiB 861 MiB 3.8 GiB 1.7 TiB 54.09 0.91 123 up 28 hdd 3.63869 1.00000 3.6 TiB 1.9 TiB 1.9 TiB 262 MiB 3.6 GiB 1.8 TiB 51.00 0.85 121 up 29 hdd 3.63869 1.00000 3.6 TiB 2.7 TiB 2.7 TiB 998 MiB 5.1 GiB 937 GiB 74.86 1.25 123 up 30 hdd 3.63869 1.00000 3.6 TiB 1.8 TiB 1.8 TiB 1.1 GiB 3.6 GiB 1.8 TiB 50.77 0.85 122 up 31 hdd 3.63869 1.00000 3.6 TiB 2.3 TiB 2.3 TiB 689 MiB 4.4 GiB 1.3 TiB 63.96 1.07 121 up TOTAL 116 TiB 70 TiB 69 TiB 20 GiB 134 GiB 47 TiB 59.73 MIN/MAX VAR: 0.43/1.57 STDDEV: 16.78 I enabled the balancer this morning, about 4 hours ago: [xxx@ceph02 ~]$ sudo ceph --cluster xxx balancer status { "last_optimize_duration": "0:00:01.119296", "plans": [], "mode": "crush-compat", "active": true, "optimize_result": "Optimization plan created successfully", "last_optimize_started": "Fri Sep 2 14:57:03 2022" } ...and lowered priority to 0.85 for the most-used OSDs (however it looks like it's slowly reverting to 1?): [xxx@ceph02 ~]$ sudo ceph --cluster xxx osd tree ID CLASS WEIGHT TYPE NAME STATUS REWEIGHT PRI-AFF -1 116.43799 root default -3 29.10950 host ceph01 0 hdd 3.63869 osd.0 up 1.00000 1.00000 1 hdd 3.63869 osd.1 up 1.00000 1.00000 2 hdd 3.63869 osd.2 up 1.00000 1.00000 3 hdd 3.63869 osd.3 up 1.00000 1.00000 4 hdd 3.63869 osd.4 up 0.95981 1.00000 5 hdd 3.63869 osd.5 up 1.00000 1.00000 6 hdd 3.63869 osd.6 up 1.00000 1.00000 7 hdd 3.63869 osd.7 up 1.00000 1.00000 -5 29.10950 host ceph02 8 hdd 3.63869 osd.8 up 1.00000 1.00000 9 hdd 3.63869 osd.9 up 1.00000 1.00000 10 hdd 3.63869 osd.10 up 1.00000 1.00000 11 hdd 3.63869 osd.11 up 0.95981 1.00000 12 hdd 3.63869 osd.12 up 1.00000 1.00000 13 hdd 3.63869 osd.13 up 1.00000 1.00000 14 hdd 3.63869 osd.14 up 1.00000 1.00000 15 hdd 3.63869 osd.15 up 1.00000 1.00000 -7 29.10950 host ceph03 16 hdd 3.63869 osd.16 up 1.00000 1.00000 17 hdd 3.63869 osd.17 up 0.95981 1.00000 18 hdd 3.63869 osd.18 up 1.00000 1.00000 19 hdd 3.63869 osd.19 up 1.00000 1.00000 20 hdd 3.63869 osd.20 up 1.00000 1.00000 21 hdd 3.63869 osd.21 up 1.00000 1.00000 22 hdd 3.63869 osd.22 up 1.00000 1.00000 23 hdd 3.63869 osd.23 up 1.00000 1.00000 -9 29.10950 host ceph04 24 hdd 3.63869 osd.24 up 1.00000 1.00000 25 hdd 3.63869 osd.25 up 1.00000 1.00000 26 hdd 3.63869 osd.26 up 0.95981 1.00000 27 hdd 3.63869 osd.27 up 1.00000 1.00000 28 hdd 3.63869 osd.28 up 1.00000 1.00000 29 hdd 3.63869 osd.29 up 1.00000 1.00000 30 hdd 3.63869 osd.30 up 1.00000 1.00000 31 hdd 3.63869 osd.31 up 1.00000 1.00000 _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to 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