The Duplicate Optical (DUPOPT) command creates a duplicate optical
volume.
The created duplicate volume is identical to the original volume except
for the volume identifier and the time created.
Performance improves significantly when you use DUPOPT instead of CPYOPT
to back up an entire volume from scratch. The DUPOPT command has the following
requirements:
- Two optical drives are required.
- The source and target volumes must have the same sector size.
- The source and target volumes can not be on opposite sides of the same
cartridge.
- The source and target device types must be the same type (for example,
optical library to optical library or optical stand-alone device to optical
stand-alone device).
- If the source media type is *WORM, the target media type can be either
*WORM or *ERASE. v If the source media type is *ERASE, the target media type
must be *ERASE.
- If the source media type is *DVD-RAM, the target media type must be *DVD-RAM.
- If the target media type is *WORM, it must be uninitialized.
- If the target media type is *ERASE, all data currently on the target volume
will be lost.
- Once the DUPOPT command begins operation, the system will not interrupt
the process. The system will not schedule any other work in the drives until
the command completes.
Use the DUPOPT command when you want to copy the entire volume or for incremental
backups of your source volume. For an entire backup, wait until your source
volume is full before you use the DUPOPT CL command.
DUPOPT always makes a complete copy of your source volume. However, you
could use it to make incremental backups of your optical volumes in the following
manner:
- Determine how often you wish to backup your source and how many backup
copies you wish to keep.
- Use DUPOPT to duplicate your source media to a target media that has a
media type of *ERASE. This will give you an exact copy of the source media.
- Continue making duplicates of your source volume as often as you wish
until your source volume becomes full.
- Once the source media is full and you have a successful final copy, you
can reuse all previous target media for backups of other source media.
- If your source media type is *WORM, prior to your final backup determine
whether or not your final target media type needs to be media type *WORM or
*ERASE.
Caution: If the DUPOPT command does not complete successfully or
it ends for any reason while processing, the backup is unsuccessful. In addition,
if the target media type is *WORM, the target volume may no longer be usable.