The dump classes to which a volume is dumped determine how the
particular dump copies are made and used. You can control the following
factors with the dump class:
- Whether the dump tapes are automatically reused when the dumped
data is no longer valid
- Whether the dump tapes can be used to restore individual data
sets
- The day of the dump cycle on which data will be dumped to the
dump class
- What to do with the newly created dump tapes
- How often to dump data to the dump class
- Whether to reset the data-set-changed indicator
- When the data on the dump volumes becomes invalid
- The kind of tape unit to use for the dump tapes
- The number of generations for which copies of the VTOC of dumped
volumes will be kept
- The expiration date to use in the tape header label
- The maximum number of dump copies to be stacked on a dump tape
assigned to this dump class
- Whether to compress and encrypt the dump data
- Whether the dump class is required or optional
The DUMPCLASS parameter of the DEFINE command provides the control
for the dump class.
There are three dump classes in the example system: ONEWEEK, TWOWEEK,
and FOURWEEK. The copies in the ONEWEEK class are kept at the computer
site and are used to restore complete volumes or individual data sets
as necessary. The copies in the TWOWEEK and FOURWEEK classes are sent
to another site to be available for returning the business to production
should a disaster occur at the computer site. Because the DUMPCLASS
parameter has many subparameters, the effect of each subparameter
is described and the DUMPCLASS parameter is built as you proceed.