Thankyou , I should be able to do it with the hooks. I have raised a feature request at BZ809172 Tim Hughes mailto:<a href="mailto:thughes@thegoldfish.org" target="_blank">thughes@thegoldfish.org</a> <div class="gmail_quote">On 2 April 2012 17:22, Daniel P. Berrange <<a href="mailto:berrange@redhat.com">berrange@redhat.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="HOEnZb"><div class="h5">On Mon, Apr 02, 2012 at 05:15:55PM +0100, Tim Hughes wrote: > Hello, > > We have been tuning our libvirt hosts and discovered that setting the > txqueuelen on vnetX devices to 2500 we can increase the network throughput > by a factor of almost 10. On an eth device it can be set by hand/rc.local > with the following instructions > <a href="http://www.cyberciti.biz/faq/gentoo-centos-rhel-debian-fedora-increasing-txqueuelen/" target="_blank">http://www.cyberciti.biz/faq/gentoo-centos-rhel-debian-fedora-increasing-txqueuelen/</a> > . Because vnetX devices are named on a 'first free' basis and they come > and go with the guests the rc.local method is not going to work. I think > this needs to be done via libvirt or possibly udev, maybe with some kind of > hook. Ideally I would like to be able to set this automatically for all > vnetX devices when they are created or even better, on a per guest basis. </div></div>You can probably do this with a hook script: <a href="http://libvirt.org/hooks.html" target="_blank">http://libvirt.org/hooks.html</a> Please also file a BZ requesting that this tunable be directly supported by libvirt. Daniel -- |: <a href="http://berrange.com" target="_blank">http://berrange.com</a> -o- <a href="http://www.flickr.com/photos/dberrange/" target="_blank">http://www.flickr.com/photos/dberrange/</a> :| |: <a href="http://libvirt.org" target="_blank">http://libvirt.org</a> -o- <a href="http://virt-manager.org" target="_blank">http://virt-manager.org</a> :| |: <a href="http://autobuild.org" target="_blank">http://autobuild.org</a> -o- <a href="http://search.cpan.org/%7Edanberr/" target="_blank">http://search.cpan.org/~danberr/</a> :| |: <a href="http://entangle-photo.org" target="_blank">http://entangle-photo.org</a> -o- <a href="http://live.gnome.org/gtk-vnc" target="_blank">http://live.gnome.org/gtk-vnc</a> :| </blockquote></div>