The Virtual Hard Disk (VHD) format is a publicly available image format specification that specifies a virtual hard disk encapsulated in a single file, capable of hosting native file systems while supporting standard disk and file operations. They are commonly used as part of the Hyper-V feature of Windows Server 2008 R2, for example. For more information about VHDs, see Additional references.

You can use Disk Management to create, attach, and detach virtual hard disks (VHDs).

Membership in Backup Operators or Administrators, or equivalent, is the minimum required to complete these procedures.

Viewing VHDs in Disk Management

VHDs appear just like physical disks in Disk Management. When a VHD has been attached (that is, made available to the system for use), it appears blue. If the disk is detached (that is, made unavailable), its icon reverts to gray.

Creating a VHD

To create a VHD

  1. On the Action menu, select Create VHD.

  2. In the Create and Attach Virtual Hard Disk dialog box, specify the location on the physical computer where you want the VHD file to be stored and the size of the VHD.

  3. In Virtual hard disk format, select Dynamically expanding or Fixed size, and then click OK.

Attaching and detaching a VHD

To make a VHD available for use (either one you have just created or another existing VHD), on the Action menu, select Attach VHD, and then specify the location of the VHD, using a fully qualified path.

To detach the VHD, which will make it unavailable, on the Action menu, select Detach VHD, or right-click the VHD in the volume list or graphical view, and then select Detach VHD. Detaching a VHD does not delete the VHD or any data stored in it.

Additional considerations

  • The path specifying the location for the VHD must be fully qualified and cannot be in the \Windows directory.

  • The minimum size for a VHD is 3 megabytes (MB).

  • A VHD can only be a basic disk.

  • Because a VHD is initialized when it is created, creating a large fixed-size VHD might take some time.

Additional references

  • Manage Disks Remotely
  • Manage Basic Volumes