Below is a list of items that you can use to determine if you should
use a target volume type of *PRIMARY or *BACKUP.
- In general, the CPYOPT to a type *PRIMARY volume gives you more flexibility,
but it requires more management of your backup volumes.
- The CPYOPT to a type *BACKUP volume provides more management and security
for your optical backup volumes, but it is less flexible.
- Use the CPYOPT command, and specify a type *PRIMARY volume, if you want
to copy data from several volumes to a single volume.
- Use the CPYOPT command, and specify a type *BACKUP volume, if you want
better security for your backup volumes. The system cannot write volumes with
type *BACKUP to with normal optical commands or user programs.
- Use the CPYOPT command and specify a type *BACKUP volume to save information
such as when the system copied directories and volumes, and the success status
of those copies.
- The biggest advantage of using the CPYOPT to a type *BACKUP volume is
that the system stores the backup control information on the backup volume.
This information includes the relationship between files on the backup volume
and the files on the primary volume. This information can be very useful if
you ever need to recover the lost source data is from the backup volume.
- Use the CPYOPT command, and specify a type *BACKUP volume, if you want
the source and target file dates (creation and change) to be identical.
- One disadvantage in using the CPYOPT command to a type *BACKUP volume
is that the system uses extra space on the backup volume to store control
information. The amount that is used is approximately 3 times the sector size
for each directory. Therefore, if CPYOPT copies 100 directories from a primary
volume to a backup volume where the sector size on the backup volume is 2KB,
the backup volume uses an additional 600KB of space. In this example 600KB
of space is used every time the command is run.