Use datastore resignaturing if you want to retain the data stored on the VMFS datastore copy.

When resignaturing a VMFS copy, ESXi assigns a new signature (UUID) to the copy, and mounts the copy as a datastore distinct from the original. All references to the original signature from virtual machine configuration files are updated.

When you perform datastore resignaturing, consider the following points:

  • Datastore resignaturing is irreversible.
  • After resignaturing, the storage device replica that contained the VMFS copy is no longer treated as a replica.
  • A spanned datastore can be resignatured only if all its extents are online.
  • The resignaturing process is fault tolerant. If the process is interrupted, you can resume it later.
  • You can mount the new VMFS datastore without a risk of its UUID conflicting with UUIDs of any other datastore from the hierarchy of device snapshots.


  • Unmount the datastore copy.
  • Perform a storage rescan on your host.


  1. In the vSphere Web Client navigator, select Global Inventory Lists > Datastores.
  2. Click the New Datastore icon.
  3. Enter the datastore name and if necessary, select the placement location for the datastore.
  4. Select VMFS as the datastore type.
  5. From the list of storage devices, select the device that has a specific value displayed in the Snapshot Volume column.
    The value present in the Snapshot Volume column indicates that the device is a copy that contains a copy of an existing VMFS datastore.
  6. Under Mount Options, select Assign a New Signature and click Next.
  7. Review the datastore configuration information and click Finish.