If you plan to use a virtual disk in Windows Server Failover Clustering (WSFC) configurations, your VMFS6 datastore must support clustered virtual disks. Use the vSphere Client to configure the clustered disk support.

For information on the use of clustered virtual disks in VM clusters, see the Setup for Windows Server Failover Clustering documentation.


Follow these guidelines when you use a datastore for clustered virtual disks:
  • The storage array supports the ATS, Write Exclusive – All Registrant (WEAR) SCSI-3 reservation type. For this type of configurations, ESXi supports only Fibre Channel arrays.
  • Storage devices that back the datastore are claimed by the NMP. ESXi does not support third-party plug-ins (MPPs) in the clustered virtual disk configurations.
  • The datastore is of VMFS6 type. You cannot expand or span the datastore.
  • The VMFS6 datastore is deployed on the storage device with the attribute Clustered VMDK Supported set to Yes.
  • Virtual disks you use for clustering are in the Thick Provision Eager Zeroed format.


  1. In the vSphere Client, navigate to the datastore.
  2. Click the Configure tab, and click General.
  3. Under Datastore Capabilities, click one of the following options next to the Clustered VMDK item.
    Option Description
    Enable To activate support for clustered virtual disks on the datastore. After you activate the support, you can place the clustered virtual disks on this VMFS datastore.
    Disable To deactivate the support. Before deactivating, make sure to power off all virtual machines with the clustered virtual disks.
  4. Confirm your configuration.