If you’re using SCVMM, however, when you create a new VM on a virtual server that’s part of a cluster, you can only store the new VM on clustered storage and make the VM highly available. You can’t use any directly attached storage on the VM. These restrictions are part of SCVMM’s design. If you want to create a VM that isn’t highly available on a clustered virtual server, you need to use the Hyper-V Manager snap-in instead of the SCVMM management snap-in.
The SCVMM 2008 documentation says this on the subject:
“It is recommended that you not deploy virtual machines that are not highly available on your host clusters. Although you can do this by using Hyper-V (VMM does not allow it), the non-highly available virtual machines will consume resources that otherwise would be available to the HAVMs.”