The Windows hibernation option creates a large system file that can increase the size of the linked-clone OS disks that are created from the parent virtual machine. Disabling the hibernation option reduces the size of linked-clones.

The Windows hibernation option creates a hidden system file, Hiberfil.sys. Windows uses this file to store a copy of system memory on the hard disk when the hybrid sleep setting is turned on. When you create a linked-clone pool, the file is created on each linked clone's OS disk.

On Windows 7 or Windows 8 virtual machines, this file can be 10GB.

Caution: When you make hibernation unavailable, the hybrid sleep setting does not work. Users can lose data if the hybrid sleep setting is turned on and a power loss occurs.


Familiarize yourself with the Windows hibernation feature. See the Microsoft Support Web site. For information about disabling hibernation on Windows 8 or Windows 7, see the Microsoft Support Web site and search for how to disable and re-enable hibernation on a computer that is running Windows.


  1. In vSphere Client, select the parent virtual machine and select Open Console.
  2. Log in to the Windows guest operating system as an administrator.
  3. Disable the hibernation option.
    1. Click Start and type cmd in the Start Search box.
    2. In the search results list, right-click Command Prompt and click Run as Administrator.
    3. At the User Account Control prompt, click Continue.
    4. At the command prompt, type powercfg.exe /hibernate off and press Enter.
    5. Type exit and press Enter.
  4. Log out of the guest operating system.


When you a create linked-clone machines from the parent virtual machine, the Hiberfil.sys file is not created on the linked-clone OS disks.