I've been trying to add a new VHD to an existing VM but am experiencing problems. when I try to add the new disk the Hyper-V manager hangs in the creating new disk step. I've then tried to expand an existing disk and then suffers a hang when the Hyper-V manager is discovering the current disk I want to expand. I've made sure there is enough free space available where I want to create the VHD. I've also tried this using a different managing machine and the 5nine Hyper-V manager but am experiencing similar problems.
The VM who's disks I'm trying to modify is a SBS 2011 and is the only DC and DNS on the network. The Hyper-V machine is a Server 2012 Core.
Any suggestions on what might be wrong?