[libvirt] qemu-kvm networking speed

Bryan_Coleman at dart.biz Bryan_Coleman at dart.biz
Thu Mar 12 20:35:22 UTC 2009

When I run iperf according to 'top' my CPU % does not even go above 2%. 
'virt-manager' CPU usage did not go above 25%.



Daniel Veillard <veillard at redhat.com> 
03/12/2009 04:28 PM
Please respond to
veillard at redhat.com

Bryan_Coleman at dart.biz
libvir-list at redhat.com
Re: [libvirt] qemu-kvm networking speed

On Thu, Mar 12, 2009 at 04:18:27PM -0400, Bryan_Coleman at dart.biz wrote:
> Thank you for the suggestion.  Switching to virtio and/or e1000 helped 
> still was not able to exceed 450Mb/s.  It took me awhile to figure out 
> had to either restart or reload libvirtd for the changes to take effect. 

> Is there anything else I could check/change to approach 1000Mb/s or 
> higher?

  I don't think any of the hardware emulation layer can be faster than
virtio, that would be very surprizing. Seems you're approaching the
limit of the capacity of the machine, I would not be surprized if you
were CPU bound at that point. There is probably tuning possibilities
but that also probably depend on other factors than just libvirt
or QEmu itself.


Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20090312/6f3b28a4/attachment-0001.htm>

More information about the libvir-list mailing list