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 Kernel 4.4 has a drop of 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 => average ~81MB/s Kernel 4.2.0-38-generic : ceph tell osd.ID => average ~109MB/s Kernel 4.4.0-24-generic : ceph tell osd.ID => average ~50MB/s Does anyone get a similar behaviour on their cluster ? Best regards -- Yoann Moulin EPFL IC-IT _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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