The most common use of our software is in a 2-node XenServer environment with local storage. This setup specifically addresses two issues:
1- HA in a 2 node pool is not reliably supported by XenServer- HA-Lizard was designed to provide predictable failover in a 2-node pool
2- local storage is converted to a form of internal SAN such that VMs can be moved live and restarted without any of the limitations of using DAS. This is done with our iSCSI-HA package and allows users to build 2-node pools without any external SAN while realizing all the functionality (mainly VM agility) of a SAN environment.
Many users are implementing HA-Lizard+iSCSI-HA to realize the scenario described above. This design is well documented in a reference design and how-to that we publish on our site.