title: Alternative to VMWare Server on Windows Server 2008 R2
body: <p>Currently we are running a VMWare Server on a Windows Server 2008 R2. The hardware specs of the machine are very good. Nonetheless, performance in virtual machines is not at all acceptable when two or more virtual machines are running at the same time (just running, not performing any CPU or disk intensive tasks). </p>
  
  <p>Hence we are looking for alternatives. VMWare's website is full of buzz words only, I cannot figure out if they provide a product fitting our requirements. But alternatives from other suppliers are also welcome.
  There are some constraints:</p>
  
  <ul>
  <li>The virtualization product must run on Windows 2008 R2 - the server will not be virtualized (hence esx is excluded)</li>
  <li>Many Virtual Machines already exist. They must be usable with the new system, or the conversion process must be simple</li>
  <li>The virtualization engine must be able to run without an interactive user session (hence VMWare Player and VirtualBox are excluded)</li>
  <li>It must be possible to reset a machine to a snapshot and to start a machine via command line from a different (i.e. not the host) machine (something like the vmrun command)</li>
  <li>Several machines must be able to run in parallel without causing an enormous drop in performance</li>
  </ul>
  
  <p>Do you have some hints for that?</p>