One of the main issues in Virtualisation is finding out where the capacity bottleneck’s are, or just to be happy that there aren’t any.
I have found the following Virtual Appliance (fully configured virtual machine) which says it will do that for you, I have not had a chance to test it yet but from the on-line demo it looks pretty good.
Check out the flash demo and download the beta from here…
http://www.vkernel.com/downloads/all/
Update, the following is a good overview of this Virtual Appliance…
http://www.dabcc.com/article.aspx?id=7529