I have been reviewing some articles on creating a 2008 R2 Core Server two node cluster. From what I have read one of the first steps is having a 2008 AD server which is attached via ISCSI to a SAN. Then I need two 2008 Core Servers to be part of this domain. These two nodes are then clustered through their connection to the AD server and by proxy through ISCSI on the AD share the SAN. So in reality a 2 node cluster really needs 3 computers at minimum? Or is there a way to create a 2 node cluster with simply two Core Servers? Could one of them host a 2008 AD VM which would somehow do the job of the physical 2008 AD server?