It seems to me that if vol_id reports the usage of the entire disk device as being raid, then that should carry over to all partitions on it, and a usage type of raid should preclude its use by anything other than raid.
It seems to me that if vol_id reports the usage of the entire disk device as being raid, then that should carry over to all partitions on it, and a usage type of raid should preclude its use by anything other than raid.