You add and remove datastores to and from an existing datastore cluster.

You can add to a datastore cluster any datastore that is mounted on a host in the vSphere Client inventory, with the following exceptions:
  • All hosts attached to the datastore must be ESXi 5.0 and later.
  • The datastore cannot be in more than one data center in the same instance of the vSphere Client.

When you remove a datastore from a datastore cluster, the datastore remains in the vSphere Client inventory and is not unmounted from the host.