'Download root disk of an OVA image as streamOptimized.'

def _fetch_image_as_ova(self, context, vi, image_ds_loc):

    vm_name = image_ds_loc.parent.basename
    image_size = images.fetch_image_ova(context, vi.instance, self._session, vm_name, vi.datastore.name, vi.dc_info.vmFolder, self._root_resource_pool)
    vi.ii.file_size = image_size
