More details, please. You ran the same test twice and performance went up from 17.5MB/s to 394MB/s? How many drives in each node, and of what kind? -Greg Software Engineer #42 @ http://inktank.com | http://ceph.com On Mon, Apr 8, 2013 at 12:38 PM, Ziemowit Pierzycki <ziemowit@xxxxxxxxxxxxx> wrote: > Hi, > > I have a 3 node SSD-backed cluster connected over infiniband (16K MTU) and > here is the performance I am seeing: > > [root@triton temp]# !dd > dd if=/dev/zero of=/mnt/temp/test.out bs=512k count=1000 > 1000+0 records in > 1000+0 records out > 524288000 bytes (524 MB) copied, 0.436249 s, 1.2 GB/s > [root@triton temp]# dd if=/dev/zero of=/mnt/temp/test.out bs=512k > count=10000 > 10000+0 records in > 10000+0 records out > 5242880000 bytes (5.2 GB) copied, 299.077 s, 17.5 MB/s > [root@triton temp]# dd if=/mnt/temp/test.out of=/dev/null bs=512k > count=1000010000+0 records in > 10000+0 records out > 5242880000 bytes (5.2 GB) copied, 13.3015 s, 394 MB/s > > Does that look right? How do I check this is not a network problem, because > I remember seeing a kernel issue related to large MTU. > > _______________________________________________ > 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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