The systems that I am looking to mirror currently are the management database for our Blackberry Enterprise Server and the configuration database for Active Directory Federation Services. In the event of power loss at the primary site I would like the databases to automatically failover to the DR site. As from what I can tell to manually failover the severs involved need to be able to connect to each other and in the event of a powerloss at the primary site I would then not be able to fail them over.

So given the above do need to place the witness at the DR site after all?