Hi, I also observe an increase in pgmap version every second or so, see snippet below. I run mimic 13.2.8 without any PG scaling/upmapping. Why does the version increase so often? May 14 12:33:50 ceph-03 journal: cluster 2020-05-14 12:33:48.521546 mgr.ceph-02 mgr.27460080 192.168.32.66:0/63 114833 : cluster [DBG] pgmap v114860: 2545 pgs: 2 active+clean+scrubbing+deep, 2543 active+clean; 195 TiB data, 249 TiB used, 1.5 PiB / 1.8 PiB avail; 4.8 MiB/s rd, 11 MiB/s wr, 1.48 kop/s May 14 12:33:50 ceph-02 journal: 2020-05-14 12:33:50.543 7fdb57c5b700 0 log_channel(cluster) log [DBG] : pgmap v114861: 2545 pgs: 2 active+clean+scrubbing+deep, 2543 active+clean; 195 TiB data, 249 TiB used, 1.5 PiB / 1.8 PiB avail; 5.6 MiB/s rd, 11 MiB/s wr, 1.21 kop/s May 14 12:33:52 ceph-02 journal: 2020-05-14 12:33:52.565 7fdb57c5b700 0 log_channel(cluster) log [DBG] : pgmap v114862: 2545 pgs: 2 active+clean+scrubbing+deep, 2543 active+clean; 195 TiB data, 249 TiB used, 1.5 PiB / 1.8 PiB avail; 8.9 MiB/s rd, 16 MiB/s wr, 1.59 kop/s The version increases every second, here from pgmap v114860 to pgmap v114862. Current cluster status: [root@gnosis]# ceph status cluster: id: --- health: HEALTH_OK services: mon: 3 daemons, quorum ceph-01,ceph-02,ceph-03 mgr: ceph-02(active), standbys: ceph-01, ceph-03 mds: con-fs2-1/1/1 up {0=ceph-08=up:active}, 1 up:standby-replay osd: 288 osds: 268 up, 268 in data: pools: 10 pools, 2545 pgs objects: 80.80 M objects, 195 TiB usage: 249 TiB used, 1.5 PiB / 1.8 PiB avail pgs: 2543 active+clean 2 active+clean+scrubbing+deep io: client: 20 MiB/s rd, 21 MiB/s wr, 578 op/s rd, 1.08 kop/s wr Thanks for any info! ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Nghia Viet Tran <Nghia.Viet.Tran@xxxxxxxxxx> Sent: 14 May 2020 03:49:38 To: Bryan Henderson; Ceph users mailing list Subject: Re: What is a pgmap? If your Ceph cluster are running on the latest version of Ceph then the the pg_autoscaler probably is the reason. After the period of time, Ceph will check the cluster status and increase/decrease the number of PG in the cluster if needed. On 5/14/20, 03:37, "Bryan Henderson" <bryanh@xxxxxxxxxxxxxxxx> wrote: I'm surprised I couldn't find this explained anywhere (I did look), but ... What is the pgmap and why does it get updated every few seconds on a tiny cluster that's mostly idle? I do know what a placement group (PG) is and that when documentation talks about placement group maps, it is talking about something else -- mapping of PGs to OSDs by CRUSH and OSD maps. -- Bryan Henderson San Jose, California _______________________________________________ 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