I noticed that the stats reported by virDomainInterfaceStats appeared to be swapped around. If the domain was downloading a lot of information, then tx_bytes would increase quickly (I'd expect rx_bytes to increase more if the domain was downloading). The problem is that xen_internal.c measures the TX/RX from the point of view of dom0. So that if dom0 is TRANSMITTING a lot of data up to the domain, then that domain is really RECEIVING it. Yes, I feel like an idiot ... Fix attached. Rich. -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903