If your deployment includes NAS arrays that support the vSphere APIs for Array Integration (VAAI), you can use the fast file clone technology, also called native NFS snapshots, to make virtual machine snapshots. With this technology, the NFS device copies the virtual machine without having the ESXi host read and write the data. This operation might reduce the time and network load when VM snapshots are created.

By default, all newly created VMs support traditional ESXi snapshot technology. To use the NFS native snapshot technology, enable it for the VM.


  • Verify that the NAS array supports the fast file clone operation with the VAAI NAS program.
  • On your ESXi host, install vendor-specific NAS plug-in that supports the fast file cloning with VAAI.
  • Follow the recommendations of your NAS storage vendor to configure any required settings on both the NAS array and ESXi. See your storage vendor documentation for more information.


  1. In the vSphere Client, right-click the virtual machine and select Edit Settings.
  2. Click the VM Options tab and expand the Advanced menu.
  3. Click Edit Configuration next to Configuration Parameters.
  4. Configure the snapshot.alwaysAllowNative parameter.
    If the parameter exists, make sure that its value is set to True. If the parameter is not present, add it and set its value to True.
    Name Value
    snapshot.alwaysAllowNative True
    Note: VMs stored on NFS datastores and configured with snapshot.alwaysAllowNative might encounter the Invalid Disk Chain error. For more information, see the VMware Knowledge Base article 89923.