title: libvirt/virsh unable to destroy vm
body: <p>I have a big problem with my kvm:<br>
  I wanted to shut down my machine "Owncloud", after the power state of "Owncloud" is "in shutdown".<br>
  When I try to destroy this machine with "virsh destroy Owncloud" I got the following:</p>
  
  <blockquote>
    <p>error: Failed to destroy domain Owncloud!<br>
    error: An error occured, but the cause is unknown</p>
  </blockquote>
  
  <p>I'm using Ubuntu 13.04 for virtualization.</p>
  
  <p>What can I do to destroy the machine without restarting the host system?</p>