Duplicate Optical (DUPOPT) command

 

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 cannot 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.

• 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 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:

1. Determine how often you wish to backup your source and how many backup copies you wish to keep.

2. 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.

3. Continue making duplicates of your source volume as often as you wish until your source volume becomes full.

4. 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.

5. 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.

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.

• Enhancements
  Several enhancements have been made since the introduction of DUPOPT command.

 

Parent topic:

Optical volume backup

Related concepts
Performance consideration for copying and duplicating optical volumes