[libvirt] is it possible to set txqueuelen on vnetX devices automatically

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 http://www.cyberciti.biz/faq/gentoo-centos-rhel-debian-fedora-increasing-... . 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. Tim Hughes mailto:thughes@thegoldfish.org