On 2020-08-18 11:13, Hans van den Bogert wrote: > I don't think it might lead to more client slow requests if you set it > to 4096 in one step, since there is a cap on how many recovery/backfill > requests there can be per OSD at any given time. > > I am not sure though, but I am happy to be proved wrong by the senior > members in this list :)
Not sure if I qualify for senior, but here are my 2 cents ... I would argue that you do want to do this in one step. Doing this in multiple steps will trigger data movement every time you change pg_num (and pgp_num for that matter). Ceph will recalculate a new mapping every time you change the pg(p)_num for a pool (or by altering CRUSH rules). osd_recovery_max_active = 1 osd_max_backfills = 1 If your cluster can't handle this than I wonder what a disk / host failure would trigger. Some on this list would argue that you also want the following setting to avoid client IO starvation: ceph config set osd osd_op_queue_cut_off high This is already the default in Octopus. Gr. Stefan _______________________________________________ ceph-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
