Nonadministrative users in the guest operating system are able to shrink virtual disks. Shrinking a virtual disk reclaims the disk's unused space. However, if you shrink a virtual disk repeatedly, the disk can become unavailable and cause a denial of service. To prevent this, disable the ability to shrink virtual disks.


  • Turn off the virtual machine.

  • Verify that you have root or administrator privileges on the virtual machine.


  1. Find the virtual machine in the vSphere Web Client inventory.
    1. Select a data center, folder, cluster, resource pool, or host.
    2. Click the Related Objects tab and click Virtual Machines.
  2. Right-click the virtual machine and click Edit Settings.
  3. Select VM Options.
  4. Click Advanced and click Edit Configuration.
  5. Add or edit the following parameters.





  6. Click OK.


When you disable this feature, you cannot shrink virtual machine disks when a datastore runs out of space.