Hey Eugen, On Wed, 2020-08-26 at 09:29 +0000, Eugen Block wrote: > Hi, > > > > root@cephosd01:~# ceph config get mds.cephosd01 osd_op_queue > > > wpq > > > root@0cephosd01:~# ceph config get mds.cephosd01 > > > osd_op_queue_cut_off > > > high > > just to make sure, I referred to OSD not MDS settings, maybe check > again? root@cephosd01:~# ceph config get osd.* osd_op_queue wpq root@cephosd01:~# ceph config get osd.* osd_op_queue_cut_off high root@cephosd01:~# ceph config get mon.* osd_op_queue wpq root@cephosd01:~# ceph config get mon.* osd_op_queue_cut_off high root@cephosd01:~# ceph config get mds.* osd_op_queue wpq root@cephosd01:~# ceph config get mds.* osd_op_queue_cut_off high root@cephosd01:~# It seems no matter which setting I query, it's always the same. Also, documentation for OSD clearly states[1] that it is the default. > I wouldn't focus too much on the MDS service, 64 GB RAM should be > enough, but you could and should also check the actual RAM usage, > of > course. But in our case it's pretty clear that the hard disks are > the > bottleneck although we have rocksDB on SSD for all OSDs. We seem > to > have a similar use case (we have nightly compile jobs running in > cephfs) just with fewer clients. Our HDDs are saturated especially > if > we also run deep-scrubs during the night, but the slow requests > have > been reduced since we changed the osd_op_queue settings for our OSDs. > > Have you checked your disk utilization? Disks are utilized roughly between 70 and 80 percent. Not sure why would operations slow down when disks are getting more utilization. If that would be the case, I'd expect Ceph to issue a warning. Have I understood correctly that the expectation is that if I used larger drives I wouldn't be seeing these warnings? I can understand that adding more disks would create better parallelisation, that's why I'm asking about larger drives. Thank you for discussing this with me, it's highly appreciated. <snip> [1] https://docs.ceph.com/docs/master/rados/configuration/osd-config-ref/#operations Kind regards, Momo. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
 |