def METHOD_NAME(self):
    def _wait_till_qemu_io_active(tag):
        for i in range(self.params.get_numeric('cmd_timeout', 20)*10):
            if process.system(self.params['grep_qemu_io_cmd'] % tag,
                              ignore_status=True, shell=True) == 0:
                break
            time.sleep(0.1)
        else:
            self.test.error('Failed to detect the active qemu-io process')
    list(map(_wait_till_qemu_io_active,
             [o.tag for o in self._client_image_objs]))