DFSMSrmm automatically adds volumes to the DFSMSrmm control data set during entry processing and when you use volumes and when no REJECT ANYUSE command for the volumes is specified. If a volume defined to DFSMSrmm is entered into a system-managed tape library without using the RMM CHANGEVOLUME command to set the volume location to the library name, DFSMSrmm updates the DFSMSrmm control data set volume record with the library name, library type, and volume entry status. DFSMSrmm does not update the home location name for the volume.

If the volume is not defined to DFSMSrmm and is entered into an automated tape library, DFSMSrmm automatically defines the volume in the DFSMSrmm control data set with information it obtains from the OAM entry user exit parameter list as follows: LOCATION, STATUS, STORGRP, MEDIATYPE, RECORDINGFORMAT, SPECIALATTRIBUTES, COMPACTION, READDATE, WRITEDATE, EXPDT, LIBRARY NAME, TYPE, ENTRY STATUS, and HOME LOCATION. This means that all volumes entered into an automated tape library must be managed by DFSMSrmm, unless the library is to be partitioned and certain volumes left undefined. See Partitioning system-managed tape libraries for details on partitioning the system-managed tape library.

Recommendation: Define all volumes to DFSMSrmm before entering them into a library. Define private volumes prior to entry into the automated tape library and set the ISMF default cartridge entry status to scratch.

If you are inserting cartridges without predefining them to DFSMSrmm, and the default entry use attribute is private, then DFSMSrmm assigns a default owner. The default owner is set to the RACF® User ID associated with the DFRMM started procedure name.