I don’t often work with passthrough disks in Hyper-V but, after configuring my Netgear ReadyNAS as an iSCSI target earlier this evening, I wanted to use it as storage for a new virtual machine. Try as I might, I could not get Hyper-V Manager to accept a physical disk as a target, despite having tried both SCSI and IDE disk controllers. Then I read the information text next to the Physical hard disk dropdown in the VM settings:
“If the physical hard disk you want to use is not listed, make sure that the disk is offline. Use Disk Management on the physical computer to manage physical hard disks.”
Doh! a classic case of RTFM… (my excuse is that it’s getting late here). After taking the disk offline I could select it and attach it to the virtual machine.