Before you create linked clones, you must disable scheduled defragmentations on Windows 7, Windows 8/8.1, and Windows 10 parent virtual machines. Windows guest operating systems schedule weekly disk defragmentations by default. Repeated defragmentation operations significantly increase the size of linked-clone OS disks and do not make disk access more efficient on linked clones.

When you create a linked-clone pool from the parent virtual machine, the linked clones share the replica's disk. Subsequent defragmentation operations do not affect the replica's disk, which is read-only. Instead, defragmentations expand each clone's OS disk.

As a best practice, defragment the parent virtual machine one time, before you take a snapshot and create the pool. The linked clones benefit from the defragmentation because they share the replica's optimized, read-only disk.

The following steps apply to Windows 7 and Windows 8. The steps might vary on different Windows operating systems.


  • Verify that the applications that you intend to deploy to the linked clones are installed on the virtual machine.
  • Verify that View Agent with View Composer Agent is installed on the virtual machine.


  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. Click Start and type defrag in the Search programs and files box.
  4. In the Programs pane, click Disk Defragmenter.
  5. In the Disk Defragmenter dialog box, click Defragment disk.
    The Disk Defragmenter consolidates defragmented files on the virtual machine's hard disk.
  6. In the Disk Defragmenter dialog box, click Configure schedule.
  7. Deselect Run on a schedule (recommended) and click OK.


Defragmentation operations will not take place on linked-clone virtual machines that are created from this parent virtual machine.