Hyper-V Host has claimed a drive that has been defined as a pass-through

I have run into a major issue that I cannot find an easy resolution. The problem is that my Hyper-V host server has claimed a disk defined as a pass through disk.

Specifically, I have a Hyper-V cluster with five servers (Cluster1 through Cluster5). I have built a server to act as a file server. It has an IDE disk for the boot drive (C:\) and two SCSI drives as pass-through volumes (D:\ and E:\).

This past weekend we shut down each virtual server on all five cluster servers but left the physical servers on so that we could replace the core switch. When I brought up all of the servers the file server couldn't see anything on the E: drive. Further investigation showed that the Hyper-V host had a new E: drive - the data that should have been visible on the file server. I haven't been able to get the drive released by the physical host so that it is usable by the virtual file server.

I have migrated the virtual machine to a different physical host and have the same trouble there.

Any ideas as to where I could look to find a resolution?