Is is SO much easier to support than MS clustering. You install, as an example, three local copies of SQL on three boxes with the same instance name and details, then Polyserve creates the virtual server and binds together the three installs into one. It's flexible, all nodes can see all drives (in contrast to another post elsewhere, Polyserve CAN share all of its drives across multiple instances) and it is easy to use. Only major issue we've seen is SharePoint -- Polyserve and SharePoint don't play nice together.