On Thu, 15 Jan 2015 11:25:44 AM Fabrizio Cuseo wrote: > What is strange is that on OSD tree I have high latency: tipically Apply > latency is between 5 and 25, but commit lattency is between 150 and 300 > (and sometimes 5/600), with 5/10 op/s and some B/s rd/wr (i have only 3 > vms, and only 1 is working now, so the cluster is really unloaded). > > I am using a pool with 3 copies, and I have increased pg_num to 256 (the > default value of 64 is too low); but OSD latency is the same with a > different pg_num value. > > I have other clusters (similar configuration, using dell 2950, dual ethernet > for ceph and proxmox, 4 x OSD with 1Tbyte drive, perc 5i controller), with > several vlms, and the commit and apply latency is 1/2ms. > > Another cluster (test cluster) with 3 x dell PE860, with only 1 OSD per > node, have better latency (10/20 ms). > > What can i check ?
POOMA U, but if you have one drive or controller that is marginal or failing, it can slow down the whole cluster. Might be worth while benching individual osd's _______________________________________________ pve-user mailing list [email protected] http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
