On Mon, Oct 17, 2016 at 6:16 PM, Nick Fisk <nick@xxxxxxxxxx> wrote: > Did you also set /check the c-states, this can have a large impact as well? Hi Nick. I did try intel_idle.max_cstate=0, and I've got quite a significant improvement as attached below. Thanks for this advice! This is still with DIRECT=1, SYNC=1, BS=4k, RW=WRITE. I wanted also to ask you about Numa. Some argue it should be disabled for high performance. My hosts are Dual Socket, 2x2630v4 2.2Ghz. Do you have any suggestions around whether enable or disable numa and what would be the Impact? Thx will simple-write-62: (groupid=14, jobs=62): err= 0: pid=2133: Thu Oct 20 12:47:58 2016 write: io=1213.8MB, bw=41421KB/s, iops=10355, runt= 30006msec clat (msec): min=2, max=81, avg= 5.99, stdev= 2.72 lat (msec): min=2, max=81, avg= 5.99, stdev= 2.72 clat percentiles (usec): | 1.00th=[ 2864], 5.00th=[ 3184], 10.00th=[ 3376], 20.00th=[ 3696], | 30.00th=[ 3984], 40.00th=[ 4576], 50.00th=[ 6048], 60.00th=[ 6688], | 70.00th=[ 7264], 80.00th=[ 7712], 90.00th=[ 8640], 95.00th=[ 9920], | 99.00th=[12480], 99.50th=[13248], 99.90th=[38656], 99.95th=[41728], | 99.99th=[81408] bw (KB /s): min= 343, max= 1051, per=1.62%, avg=669.64, stdev=160.04 lat (msec) : 4=30.01%, 10=65.31%, 20=4.53%, 50=0.12%, 100=0.02% cpu : usr=0.04%, sys=0.54%, ctx=636287, majf=0, minf=1905 IO depths : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0% submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% issued : total=r=0/w=310721/d=0, short=r=0/w=0/d=0 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com