I have 4 physical hard drives, 2 of them are 150GB and 2 of them are 1000GB. Both are mirrored at the pre O/S level in order to provide redundancy. On the 150GB mirror I installed the host operating system (Win Server 2008 R2 with Hyper-V) and the 1000GB mirror is just a Data drive. I've created my Virtual server in Hyper-V and allocated it 500GB from the 1000GB mirror. When I start up the virtual Server in order to install the o/s I will be asked whether to partition this "Virtual hard drive" ie have a C: drive for the virtual o/s and a d: drive for the virtual data. Of course they would be on the same physical disk anyway so should I bother partitioning the Virtual 500GB drive. Hope this is clear enough.