Hello, > Am running ubuntu 16 with kernel 4.4-0.31-generic and my speed are similar. do you have journal on disk too ? > I did tests on ubuntu 14 and Ubuntu 16 and the speed is similar. I have around > 80-90MB/s of OSD speeds in both operating systems ok and could you do bench with kernel 4.2 ? just to see if you have better throughput. Thanks > Only issue am observing now with ubuntu 16 is sometime osd fails on rebooting > until i start them manually or adding starting commands in rc.local. in my case, it's a test environment, so I don't have notice those behaviours -- Yoann > On Mon, Jul 25, 2016 at 6:45 PM, Yoann Moulin <yoann.moulin@xxxxxxx > <mailto:yoann.moulin@xxxxxxx>> wrote: > > Hello, > > (this is a repost, my previous message seems to be slipping under the radar) > > Does anyone get a similar behaviour to the one described below ? > > I found a big performance drop between kernel 3.13.0-88 (default kernel on > Ubuntu Trusty 14.04) or kernel 4.2.0 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 on > - Each cluster has 5 nodes strictly identical. > - Each node has 10 OSDs. > - Journals are on the disk. > > Kernel 4.4 has a drop of more than 50% compared to 4.2 > Kernel 4.4 has a drop of 40% compared to 3.13 > > details below : > > With the 3 kernel I have the same performance on disks : > > Raw benchmark: > dd if=/dev/zero of=/dev/sdX bs=1M count=1024 oflag=direct => average ~230MB/s > dd if=/dev/zero of=/dev/sdX bs=1G count=1 oflag=direct => average ~220MB/s > > Filesystem mounted benchmark: > dd if=/dev/zero of=/sdX1/test.img bs=1G count=1 => average ~205MB/s > dd if=/dev/zero of=/sdX1/test.img bs=1G count=1 oflag=direct => average ~214MB/s > dd if=/dev/zero of=/sdX1/test.img bs=1G count=1 oflag=sync => average ~190MB/s > > Ceph osd Benchmark: > Kernel 3.13.0-88-generic : ceph tell osd.ID bench => average ~81MB/s > Kernel 4.2.0-38-generic : ceph tell osd.ID bench => average ~109MB/s > Kernel 4.4.0-24-generic : ceph tell osd.ID bench => average ~50MB/s > > I did new benchmarks then on 3 new fresh clusters. > > - Each cluster has 3 nodes strictly identical. > - Each node has 10 OSDs. > - Journals are on the disk. > > bench5 : Ubuntu 14.04 / Ceph Infernalis > bench6 : Ubuntu 14.04 / Ceph Jewel > bench7 : Ubuntu 16.04 / Ceph jewel > > this is the average of 2 runs of "ceph tell osd.* bench" on each cluster (2 x 30 > OSDs) > > bench5 / 14.04 / Infernalis / kernel 3.13 : 54.35 MB/s > bench6 / 14.04 / Jewel / kernel 3.13 : 86.47 MB/s > > bench5 / 14.04 / Infernalis / kernel 4.2 : 63.38 MB/s > bench6 / 14.04 / Jewel / kernel 4.2 : 107.75 MB/s > bench7 / 16.04 / Jewel / kernel 4.2 : 101.54 MB/s > > bench5 / 14.04 / Infernalis / kernel 4.4 : 53.61 MB/s > bench6 / 14.04 / Jewel / kernel 4.4 : 65.82 MB/s > bench7 / 16.04 / Jewel / kernel 4.4 : 61.57 MB/s > > If needed, I have the raw output of "ceph tell osd.* bench" > > Best regards _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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