If you intend to populate the system-managed tape library with new scratch volumes, you do not need to explicitly define them to DFSMSrmm. During entry processing, with DFSMSrmm active, DFSMSrmm automatically records information about each volume in its control data set. DFSMSrmm uses the defaults you specified in ISMF for the library entry values; you should set the default entry status to scratch. See Partitioning system-managed tape libraries for additional information.