DFSMSrmm tape label support

DFSMSrmm supports these tape label types:

IBM standard labels (SL)
ISO/ANSI labels (AL)
Both IBM standard and user header or trailer labels (SUL)
Both ISO/ANSI and user header or trailer labels (AUL)
No labels (NL)

You can explicitly use AL, SL, and NL label types when you define volumes to DFSMSrmm. Although a tape is defined to DFSMSrmm as SL or AL, a user can still process it as SUL or AUL. A user could ask for a non-specific volume by specifying LABEL=(,SUL) and create an SL volume or SUL volume without affecting DFSMSrmm. DFSMSrmm records the value specified in the JCL.

DFSMSrmm provides support for ISO/ANSI Version 3 and ISO/ANSI Version 4 labels. You can provide the current ISO/ANSI label version of a volume that you define to DFSMSrmm. Then you can use the DFSMSrmm EDGINERS utility to initialize the tape with either ISO/ANSI Version 3 or ISO/ANSI Version 4 labels.

DFSMSrmm supports no label (NL) for private volumes and for scratch tapes in a system-managed automated tape library and private volumes in a non-system-managed tape library. If you use the IFG019VM volume mount installation exit, DFSMSrmm supports no label (NL) for scratch tapes in a non-system-managed tape library. All other scratch tapes must be standard label tapes. DFSMSrmm allows the creation of no label tapes from standard label scratch volumes by changing the volume to master status and setting the initialize release action so that the tape is relabeled as a standard label tape when returned to scratch. DFSMSrmm also overrides the logical volume serial number generated by OPEN for NL output to scratch tapes, so that the correct volume serial number is used for cataloging data sets. Nonstandard labels (NSL) can be used but only if the volume is not defined to DFSMSrmm. How does DFSMSrmm validate tape mounts? describes how DFSMSrmm validates volume usage and does not allow the processing of certain label types.

DFSMSrmm also supports the use of bypass label processing (BLP) for:

Volumes that are either not defined to DFSMSrmm or volumes that DFSMSrmm should ignore.
Non-scratch (user and master status) volumes that are used for input processing, and only those user status volumes that are used for output processing. You can select this system option in the EDGRMMxx parmlib member using the OPTION BLP(RMM) command.
Non-scratch (user and master status) volumes that are used for input processing, or user, master and scratch tapes that are used for output processing. You can select this option in the EDGRMMxx parmlib member using the OPTION BLP(NORMM) command.
When BLP is used with scratch tapes, DFSMSrmm changes the volume to master status. DFSMSrmm also sets the initialize volume release action to ensure that the volume has a valid standard label before it returns to scratch status. When a volume is written with BLP, DFSMSrmm can no longer perform the 44-character data set name check for the files on the volume.

For BLP output to a non-specific volume, DFSMSrmm does not check the file sequence number. For example, LABEL=(2,BLP) can be used. For non-BLP requests, DFSMSrmm restricts the use to LABEL=(1,label_type).

The data set information for files processed with BLP is only updated for output to first file on a volume. All other types of BLP requests change only the volume information such as the date last read and the date last written. Also for BLP output requests, the data set information is only updated in the DFSMSrmm control data set when the data set is closed.