Specifying duplexing for backup tapes

The duplex tape option creates two identical tapes in parallel, with one tape designated as the original and one the alternate. To create duplex backup tapes, specify:
SETSYS DUPLEX(BACKUP(Y))
If duplexing is not desired for your backup tapes, specify:
SETSYS DUPLEX(BACKUP(N))

The DFSMShsm default is no duplexing.