On Fri, Oct 19, 2018 at 10:06:06AM +0200, Wido den Hollander wrote: > > > On 10/19/18 7:51 AM, xiang....@iluvatar.ai wrote: > > Hi! > > > > I use ceph 13.2.1 (5533ecdc0fda920179d7ad84e0aa65a127b20d77) mimic > > (stable), and find that: > > > > When expand whole cluster, i update pg_num, all succeed, but the status > > is as below: > > cluster: > > id: 41ef913c-2351-4794-b9ac-dd340e3fbc75 > > health: HEALTH_WARN > > 3 pools have pg_num > pgp_num > > > > Then i update pgp_num too, warning miss. > > > > What makes me confused is that when i create whole cluster at first time, > > i use "ceph osd create pool pool_name pg_num", the pgp_num is auto equal > > to pg_num. > > > > But "ceph osd set pool pool_name pg_num" not. > > > > Why does this design? > > > > Why do not auto update pgp_num when update pg_num? > > > > Because when changing pg_num only the Placement Groups are created, data > isn't moving yet. pgp_num, Placement Groups for Placement influences how > CRUSH works. > > When you change that value data actually starts to move. > > pgp_num can never be larger then pg_num though. > > Some people choose to increase pgp_num in small steps so that the data > migration isn't massive. > > Wido >
I get what you mean. Maybe provide a option to start to move when set pg_num is cool for people who do expand thing in night so do not care how massive the data migration. > > Thanks > > > > _______________________________________________ > > ceph-users mailing list > > ceph-users@lists.ceph.com > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > -- Best Regards Dai Xiang _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
