Assume I have a Windows 2008 R2 clustered environment where one disk on my SAN acts as the quorum disk and another acts as the data disk for the clustered nodes. In this environment when the first clustered node goes down the 2nd one kicks in and the users have all their data via disk 2.in the SAN. R2 offers something called shared cluster volume as well which sounds like again it's a disk on my SAN. What does it do differently in the scenario I presented where one node goes down? What is it's purpose? It's not that clear to me.