On Thu, Jan 19, 2017 at 8:51 AM, 许雪寒 <xuxuehan@xxxxxx> wrote: > Hi, everyone. > > > > Recently, we did some stress test on ceph using three machines. We tested > the IOPS of the whole small cluster when there are 1~8 OSDs per machines > separately and the result is as follows: > > > > OSD num per machine fio iops > > 1 > 10k > > 2 > 16.5k > > 3 > 22k > > 4 > 23.5k > > 5 > 26k > > 6 > 27k > > 7 > 27k > > 8 > 28k > > > > As shown above, it seems that there is some kind of bottleneck when there > are more than 4 OSDs per machine. Meanwhile, we observed that the CPU %idle > during the test, shown below, has also some kind of correlation with the > number of OSDs per machine. > > > > OSD num per machine CPU idle > > 1 > 74% > > 2 > 52% > > 3 > 30% > > 4 > 25% > > 5 > 24% > > 6 > 17% > > 7 > 14% > > 8 > 11% > > > > It seems that with the number of OSDs per machine increasing, the CPU idle > time is reducing and the reduce rate Is also decreasing, can we come to the > conclusion that CPU is the performance bottleneck in this test? Impossible to say without looking at what else was bottlenecked, such as the network or the client. John > > > Thank youJ > > > _______________________________________________ > 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
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