Someone who's got data regarding this should file a bug report, it sounds like a quick fix for defaults if this holds true. On Sat, May 20, 2023, at 00:59, Hector Martin wrote:
On 17/05/2023 03.07, 胡 玮文 wrote:
Hi Sake,
We are experiencing the same. I set “osd_mclock_cost_per_byte_usec_hdd” to 0.1 (default is 2.6) and get about 15 times backfill speed, without significant affect client IO. This parameter seems calculated wrongly, from the description 5e-3 should be a reasonable value for HDD (corresponding to 200MB/s). I noticed this default is originally 5.2, then changed to 2.6 to increase the recovery speed. So I suspect the original author just convert the unit wrongly, he may want 5.2e-3 but wrote 5.2 in code.
But all this may be not important in the next version. I see the relevant code is rewritten, and this parameter is now removed.
high_recovery_ops profile works very poorly for us. It increase the average latency of client IO from 50ms to about 1s.
Weiwen Hu
Thank you for this, that parameter indeed seems completely wrong (assuming it means what it says on the tin). After changing that my Quincy cluster is no recovering at a much more reasonable speed.
- Hector _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io