Configuring pass-through disks

This objective has thus far been concerned primarily with VHDs, areas of space on a physical disk drive allocated for use by VMs. However, it is also possible for VMs to access physical disks directly.
A pass-through disk is a type of virtual disk that points to a physical disk drive installed on the host computer. When you add a hard drive to any of the controllers in a VM, you have the option of selecting a physical hard disk as opposed to a virtual one.
To add a physical hard disk to a VM, the VM must have exclusive access to it. This means that you must first take the disk offline in the parent OS by using the Disk Management snap-in, as shown in Figure 3-19, or the Diskpart.exe utility. Once the disk is offline, it will be available for selection in the Physical Hard Disk drop-down list.

FIGURE 3-19 An offline disk in the Disk Management snap-in