If your using hdd for monitor servers. Check their load. It might be the issue there. On Fri, Feb 22, 2019 at 1:50 PM M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: > > ceph-mon disk with 500G with HDD (not journals/SSDs). Yes, mon use > folder on FS on a disk > > On Fri, Feb 22, 2019 at 5:13 PM David Turner <drakonstein@xxxxxxxxx> wrote: > > > > Mon disks don't have journals, they're just a folder on a filesystem on a disk. > > > > On Fri, Feb 22, 2019, 6:40 AM M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: > >> > >> ceph mons looks fine during the recovery. Using HDD with SSD > >> journals. with recommeded CPU and RAM numbers. > >> > >> On Fri, Feb 22, 2019 at 4:40 PM David Turner <drakonstein@xxxxxxxxx> wrote: > >> > > >> > What about the system stats on your mons during recovery? If they are having a hard time keeping up with requests during a recovery, I could see that impacting client io. What disks are they running on? CPU? Etc. > >> > > >> > On Fri, Feb 22, 2019, 6:01 AM M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: > >> >> > >> >> Debug setting defaults are using..like 1/5 and 0/5 for almost.. > >> >> Shall I try with 0 for all debug settings? > >> >> > >> >> On Wed, Feb 20, 2019 at 9:17 PM Darius Kasparavičius <daznis@xxxxxxxxx> wrote: > >> >> > > >> >> > Hello, > >> >> > > >> >> > > >> >> > Check your CPU usage when you are doing those kind of operations. We > >> >> > had a similar issue where our CPU monitoring was reporting fine < 40% > >> >> > usage, but our load on the nodes was high mid 60-80. If it's possible > >> >> > try disabling ht and see the actual cpu usage. > >> >> > If you are hitting CPU limits you can try disabling crc on messages. > >> >> > ms_nocrc > >> >> > ms_crc_data > >> >> > ms_crc_header > >> >> > > >> >> > And setting all your debug messages to 0. > >> >> > If you haven't done you can also lower your recovery settings a little. > >> >> > osd recovery max active > >> >> > osd max backfills > >> >> > > >> >> > You can also lower your file store threads. > >> >> > filestore op threads > >> >> > > >> >> > > >> >> > If you can also switch to bluestore from filestore. This will also > >> >> > lower your CPU usage. I'm not sure that this is bluestore that does > >> >> > it, but I'm seeing lower cpu usage when moving to bluestore + rocksdb > >> >> > compared to filestore + leveldb . > >> >> > > >> >> > > >> >> > On Wed, Feb 20, 2019 at 4:27 PM M Ranga Swami Reddy > >> >> > <swamireddy@xxxxxxxxx> wrote: > >> >> > > > >> >> > > Thats expected from Ceph by design. But in our case, we are using all > >> >> > > recommendation like rack failure domain, replication n/w,etc, still > >> >> > > face client IO performance issues during one OSD down.. > >> >> > > > >> >> > > On Tue, Feb 19, 2019 at 10:56 PM David Turner <drakonstein@xxxxxxxxx> wrote: > >> >> > > > > >> >> > > > With a RACK failure domain, you should be able to have an entire rack powered down without noticing any major impact on the clients. I regularly take down OSDs and nodes for maintenance and upgrades without seeing any problems with client IO. > >> >> > > > > >> >> > > > On Tue, Feb 12, 2019 at 5:01 AM M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: > >> >> > > >> > >> >> > > >> Hello - I have a couple of questions on ceph cluster stability, even > >> >> > > >> we follow all recommendations as below: > >> >> > > >> - Having separate replication n/w and data n/w > >> >> > > >> - RACK is the failure domain > >> >> > > >> - Using SSDs for journals (1:4ratio) > >> >> > > >> > >> >> > > >> Q1 - If one OSD down, cluster IO down drastically and customer Apps impacted. > >> >> > > >> Q2 - what is stability ratio, like with above, is ceph cluster > >> >> > > >> workable condition, if one osd down or one node down,etc. > >> >> > > >> > >> >> > > >> Thanks > >> >> > > >> Swami > >> >> > > >> _______________________________________________ > >> >> > > >> ceph-users mailing list > >> >> > > >> ceph-users@xxxxxxxxxxxxxx > >> >> > > >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > >> >> > > _______________________________________________ > >> >> > > ceph-users mailing list > >> >> > > ceph-users@xxxxxxxxxxxxxx > >> >> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
