On Thu, Jun 23, 2016 at 9:01 AM, Yoann Moulin <yoann.mou...@epfl.ch> wrote: > Le 23/06/2016 08:25, Sarni Sofiane a écrit : >> Hi Florian, >> > > >> On 23.06.16 06:25, "ceph-users on behalf of Florian Haas" >> <ceph-users-boun...@lists.ceph.com on behalf of flor...@hastexo.com> wrote: >> >>> On Wed, Jun 22, 2016 at 10:56 AM, Yoann Moulin <yoann.mou...@epfl.ch> wrote: >>>> Hello Florian, >>>> >>>>> On Tue, Jun 21, 2016 at 3:11 PM, Yoann Moulin <yoann.mou...@epfl.ch> >>>>> wrote: >>>>>> Hello, >>>>>> >>>>>> I found a performance drop between kernel 3.13.0-88 (default kernel on >>>>>> Ubuntu >>>>>> Trusty 14.04) and kernel 4.4.0.24.14 (default kernel on Ubuntu Xenial >>>>>> 16.04) >>>>>> >>>>>> ceph version is Jewel (10.2.2). >>>>>> All tests have been done under Ubuntu 14.04 >>>>> >>>>> Knowing that you also have an internalis cluster on almost identical >>>>> hardware, can you please let the list know whether you see the same >>>>> behavior (severely reduced throughput on a 4.4 kernel, vs. 3.13) on >>>>> that cluster as well? >>>> >>>> ceph version is infernalis (9.2.0) >>>> >>>> Ceph osd Benchmark: >>>> >>>> Kernel 3.13.0-88-generic : ceph tell osd.ID => average ~84MB/s >>>> Kernel 4.2.0-38-generic : ceph tell osd.ID => average ~90MB/s >>>> Kernel 4.4.0-24-generic : ceph tell osd.ID => average ~75MB/s >>>> >>>> The slow down is not as much as I have with Jewel but it is still present. >>> >>> But this is not on precisely identical hardware, is it? >> >> All the benchmarks were run on strictly identical hardware setups per node. >> Clusters differ slightly in sizes (infernalis vs jewel) but nodes and OSDs >> are identical. > > One thing differ in the osd configuration, on the Jewel cluster, we have > journal > on disk, on the Infernalis cluster, we have journal on SSD (S3500) > > I can restart my test on a Jewel cluster with journal on SSD if needed. > I can do as well a test on an Infernalis cluster with journal on disk.
I'd suggest that the second option is probably more meaningful to test. What I find curious is that no-one else on the list has apparently run into this. Any Ubuntu xenial users out there, or perhaps folks on trusty who choose to install linux-image-generic-lts-xenial? Cheers, Florian _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
