On Tue, Jan 14, 2014 at 10:38 PM, Blaster <Blaster@556nato.com> wrote:
On 1/14/2014 11:04 AM, Andrew Cathrow wrote:
=20 Did you compare virtio-block to virto-scsi, the former will likely outperform the latter. =20 =20 No, but I have been meaning to, out of curiosity. =20 But why do you say virto-blk will be faster than virtio-scsi? The virtio-scsi wiki claims equal performance. That's also what I read but ... this presentation: = http://www.linux-kvm.org/wiki/images/f/f9/2012-forum-virtio-blk-performanc= e-improvement.pdf claims claims: "virtio-blk is about ~3 times faster than virtio-scsi in my = setup" o_O So testing is definitely a good idea. =20 I've been trying to get some real numbers of the performance = differences using iozone, but the numbers are all over the place, both on the HV = and the guests, so not very meaningful. Not an iozone expert, so still =
--Apple-Mail=_9F9CD89E-026E-4211-8B99-308F3B2B5026 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 I finally found time to switch from virtio-scsi to virtio. Seems to = have make a big difference. The windows VMs boot faster, web pages load faster, same with the Fedora = 20 VMs.=20 Everything just feels smoother. I found this interesting presentation: = http://events.linuxfoundation.org/sites/events/files/slides/CloudOpen2013_= Khoa_Huynh_v3.pdf Claims virtio blk and scsi are the same speed. Although, it doesn=92t = mention if this was with or without data plane enabled. When will data plane be the default? On Jan 15, 2014, at 3:11 AM, Sander Grendelman <sander@grendelman.com> = wrote: trying to
figure out what I'm doing wrong there as well. =20 I've also done some (relatively simple) testing with fio.
--Apple-Mail=_9F9CD89E-026E-4211-8B99-308F3B2B5026 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 <html><head><meta http-equiv=3D"Content-Type" content=3D"text/html = charset=3Dwindows-1252"></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; -webkit-line-break: = after-white-space;"><div><br></div><div>I finally found time to switch = from virtio-scsi to virtio. Seems to have make a big = difference.</div><div><br></div><div>The windows VMs boot faster, web = pages load faster, same with the Fedora 20 = VMs. </div><div>Everything just feels = smoother.</div><div><br></div><div>I found this interesting = presentation:</div><div><a = href=3D"http://events.linuxfoundation.org/sites/events/files/slides/CloudO= pen2013_Khoa_Huynh_v3.pdf">http://events.linuxfoundation.org/sites/events/= files/slides/CloudOpen2013_Khoa_Huynh_v3.pdf</a></div><div><br></div><div>= Claims virtio blk and scsi are the same speed. Although, it = doesn=92t mention if this was with or without data plane = enabled.</div><div><br></div><div>When will data plane be the = default?</div><div><br></div><br><div><div>On Jan 15, 2014, at 3:11 AM, = Sander Grendelman <<a = href=3D"mailto:sander@grendelman.com">sander@grendelman.com</a>> = wrote:</div><br class=3D"Apple-interchange-newline"><blockquote = type=3D"cite">On Tue, Jan 14, 2014 at 10:38 PM, Blaster <<a = href=3D"mailto:Blaster@556nato.com">Blaster@556nato.com</a>> = wrote:<br><blockquote type=3D"cite">On 1/14/2014 11:04 AM, Andrew = Cathrow wrote:<br><blockquote type=3D"cite"><br>Did you compare = virtio-block to virto-scsi, the former will likely<br>outperform the = latter.<br></blockquote><br><br>No, but I have been meaning to, out of = curiosity.<br><br>But why do you say virto-blk will be faster than = virtio-scsi? The<br>virtio-scsi wiki claims equal = performance.<br></blockquote>That's also what I read but ... this = presentation:<br><a = href=3D"http://www.linux-kvm.org/wiki/images/f/f9/2012-forum-virtio-blk-pe= rformance-improvement.pdf">http://www.linux-kvm.org/wiki/images/f/f9/2012-= forum-virtio-blk-performance-improvement.pdf</a><br>claims<br>claims: = "virtio-blk is about ~3 times faster than virtio-scsi in my setup" = o_O<br>So testing is definitely a good idea.<br><blockquote = type=3D"cite"><br>I've been trying to get some real numbers of the = performance differences<br>using iozone, but the numbers are all over = the place, both on the HV and the<br>guests, so not very meaningful. = Not an iozone expert, so still trying to<br>figure out what = I'm doing wrong there as well.<br></blockquote><br>I've also done some = (relatively simple) testing with = fio.<br></blockquote></div><br></body></html>= --Apple-Mail=_9F9CD89E-026E-4211-8B99-308F3B2B5026--