Duplex tape creation

To specify duplexing for backup and migration volumes, issue the SETSYS command with the keyword DUPLEX. BACKUP is an optional subparameter that specifies whether duplex alternates will be made for backup volumes. MIGRATION is another optional subparameter that specifies whether duplex alternates will be made for migration volumes. You can also specify that duplexing occurs for both backup and migration volumes. Remember that specifying duplexing (backup or migration) also affects recycle output processing.

Note: When you specify either BACKUP or MIGRATION with no subparameter, the default is Y. If you do not specify DUPLEX and either of its subparameters, duplexing does not occur.

For more information about the SETSYS command syntax and the DUPLEX parameter, see z/OS DFSMShsm Storage Administration.