On Tue, Jun 12, 2012 at 12:55:48AM +0200, Dennis Jacobfeuerborn wrote: > How exactly do you test the bandwidth (tools) and do you only test the > connection to an external machine or have you also tested the bandwidth > between guest and host and this guest and another one on the same host? Netperf. The test is to another server on the LAN. From the KVM host itself to the server, from the same bridged interface, it tests at just under wire speed (with server-grade GigE Intel NICs on both). But from the VMs, not. We don't care about speed between guest and host or between guests. All of the production use of the VMs where speed matters is in connections to servers and workstations elsewhere on the LAN. That's not to say I can't do those tests if they are of diagnostic use. Just that the only goal that currently matters is connection speed from the VMs to other systems across the LAN. The VM host is a recent 16-core machine, lightly loaded (8 VMs at present, none doing much). I've seen mention of tunings for specific NICs. Is there a table that correlates NIC models with suggesting tuning somewhere? Whit _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users