'The filesystem is created with no ``refquota`` property if the maximum
size is unspecified.'

def test_no_maximum_size(self):

    mount_root = FilePath(self.mktemp())
    pool_name = create_zfs_pool(self)
    pool = StoragePool(reactor, pool_name, mount_root)
    service = service_for_pool(self, pool)
    volume = service.get(MY_VOLUME)
    d = pool.create(volume)
    def created_filesystem(filesystem):
        refquota = subprocess.check_output(['zfs', 'get', '-H', '-o', 'value', 'refquota', filesystem.name]).strip()
        self.assertEqual('none', refquota)
    d.addCallback(created_filesystem)
    return d
