havirt is a meta package which uses virsh to manipulate libvirt domains on multiple nodes with a shared storage such as iSCSI.
The only advantage to havirt over virsh is reporting on an entire cluster, ensuring a domain (virtual) is not run on more than one node (hypervisor).
Written in Perl, it is designed to be extensible for anyone familiar with that language.
havirt is available via svn at http://svn.dailydata.net/svn/havirt/stable, or it can be viewed via the webui at http://svn.dailydata.net/