The TSM4.2 Adminguide states: "the UPDATE LIBVOLUME command lets you change the status of a volume in an automated lib from scratch to private, or private to scatch. However, you cannot change the status of a volume from private to scratch if the volume belongs to a storage pool."
Well, When there is real need to pull some private volume (empty) out of a storage pool and re-use for other backup, how can you do that?
