[ceph-users] Re: objects misplaced jumps up at 5%

Does changing `target_max_misplaced_ratio` result in more PGP being created in each cycle of the remapping? Would this result in fewer copies of data or just more PGs being processed in each batch during a change of PG numbers? What is a safe value to raise `target_max_misplaced_ratio` to, given

[ceph-users] Re: objects misplaced jumps up at 5%

Dear All, great advice - thank you all so much. I've changed the pgp to 8192 (it had already risen to 11857) and see how this works. The target_max_misplaced_ratio looks like a useful control. It's a shame the ceph pg calc page doesn't have more advice for people using

[ceph-users] Re: objects misplaced jumps up at 5%

Hi, I’ve just read a post that describe the exact behavior you describe. https://ceph.io/rados/new-in-nautilus-pg-merging-and-autotuning/ There is a config option named target_max_misplaced_ratio, which defaults to 5%. You can change this to accelerate the remap process. Hopes that’s helpful.

[ceph-users] Re: objects misplaced jumps up at 5%

Continuing on this topic, is it only possible to increase the count of placement group (PG) quickly, but the associated placement group placeholder (PGP) values can only increase in smaller increments of 1-3? Each increase of the PGP requires a rebalancing and backfill again of lots of PGs? I am w

[ceph-users] Re: objects misplaced jumps up at 5%

>> I think you found the answer! >> >> When adding 100 new OSDs to the cluster, I increased both pg and pgp >> from 4096 to 16,384 >> > > Too much for your cluster, 4096 seems sufficient for a pool of size 10. > You can still reduce it relatively cheaply while it hasn't been fully > actuated y

[ceph-users] Re: objects misplaced jumps up at 5%

Hi Paul, I think you found the answer! When adding 100 new OSDs to the cluster, I increased both pg and pgp from 4096 to 16,384 ** [root@ceph1 ~]# ceph osd pool set ec82pool pg_num 16384 set pool 5 pg_num to 16384 [root@ceph1 ~]# ceph osd pool set ec82pool pgp_nu

[ceph-users] Re: objects misplaced jumps up at 5%

On 2020-09-28 11:45, Jake Grimmett wrote: > To show the cluster before and immediately after an "episode" > > *** > > [root@ceph7 ceph]# ceph -s > cluster: > id: 36ed7113-080c-49b8-80e2-4947cc456f2a > health: HEALTH_WARN >

[ceph-users] Re: objects misplaced jumps up at 5%

Hi Stefan, many thanks for your good advice. We are using ceph version 14.2.11 There is an issue with full osds - I'm not sure it's causing this misplaced jump problem; I've reweighting the most full osds on several consecutive days to reduce the number of nearfull osds, and it seems to have no