'Relocate the volume.
The move type will be moveAllDiskBackingsAndAllowSharing.'

def _relocate_vmdk_volume(self, volume_ref, res_pool, datastore, host=None):

    client_factory = self._session.vim.client.factory
    spec = vm_util.relocate_vm_spec(client_factory, datastore=datastore, host=host)
    spec.pool = res_pool
    task = self._session._call_method(self._session.vim, 'RelocateVM_Task', volume_ref, spec=spec)
    self._session._wait_for_task(task)
