I entered DUP UNIT 2C00 to UNIT 2C01 and the volume label on the receiving pack (2C01) stayed the same, it did not get 2C00's label.
To avoid having to change the DASD volume label after the DUPLICATE, just include options IVORG UND OVORG UND NEWLAB (VOL ORIG).
This tells HiDRO to completely ignore anything about the logical structure of the input and output units and strictly do a physical copy from one to the other.
The command would look like:
DUP UNIT 2C00 TO UNIT 2C01 ( IVORG UND OVORG UND NEWLAB (VOL ORIG)
HiDRO wants to preserve the target volser unless you specifically tell it not to or there isn't one to begin with.
Also, the NEWLAB option will not trigger a FORMAT of the entire volume and no additional overhead will be added by including it, therefore, the DUP operation will use the same amount of time and same number of I/O's.