title: How to benchmark virtual machines
body: <p>I am trying to perform a fair comparison of XenServer vs ESX and one comparison I would like to make is performance with multiple VMs. Does anyone know how to go about benchmarking VM performance in a fair way?</p>
  
  <p>On each server I would like to run a fixed number of XP/Vista VMs (for example 8) and have some measure of how quickly each one runs when under load. Ideally I would like some benchmark of the overall system (CPU/Memory/Disk/Network) rather than just one aspect.</p>
  
  <p>It seems to me this is actually a very tricky thing to do and obtain any meaningful results so would be grateful for any suggestions!</p>
  
  <p>I would also be interested to see any existing reports or comparisons that have been published (preferably independent rather than vendor biased!)</p>