A system is provided to support dynamically flexible data definitions and storage requirements in a data processing system. The present invention separates processing of data unit requirements from the selection of which storage subsystems to use for storage by using a storage methodologies inventory. The present invention provides a system to support dynamically flexible data definitions and storage requirements in a data processing system. A virtual stored data management subsystem contains one or more hosts. A plurality of virtual data units are functionally coupled to the one or more hosts. The plurality of virtual data units includes associated management information such that the management information provides first and second boundaries. The first and second boundaries limit preferences in which to store the virtual data units with the stored data management subsystem.