That sounds about right. There was some prior discussion about this on the openstack-operators group with similar results.
We use virtio-scsi in one of our clouds because testing (and production) has shown that volumes attached via virtio-scsi are better able to participate in mdadm and zfs. For that particular cloud, that's worth the performance loss. On Fri, Mar 31, 2017 at 9:21 AM, shubjero <[email protected]> wrote: > Hi all, > > I've recently done some disk benchmarks (dd and bonnie++) between > instances with virtio-blk and with virtio-scsi and found that on my test > bed virtio-scsi performed 11.68% slower for writes and 4.83% slower for > reads. I wasn't expecting a performance loss with virtio-scsi. Has anyone > else experienced this? I was looking at using virtio-scsi to gain > discard/trim support but not if it results in a net loss in disk > performance. > > Test bed details: > Ubuntu 14.04 LTS > Kernel: 3.13.0-111-generic > Libvirt:1.3.1-1ubuntu10.6~cloud0 > qemu:2.5+dfsg-5ubuntu10.5~cloud0 > > Attached are the detailed results of the benchmarking. I am going to > pursue some tests with Ubuntu 16.04 as the host. > > Thanks, > > Jared > > _______________________________________________ > Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/ > openstack > Post to : [email protected] > Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/ > openstack > >
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