The backup attribute BACKUP FREQUENCY governs how frequently the
data sets can be backed up automatically. Backup frequency is a management
class attribute. This attribute specifies the number of days that
must have elapsed since the last backup before the data set can be
backed up again automatically, even though the data set may have changed
and the volume it resides on is undergoing backup processing. For
example, the data set will not be backed up because the frequency
specification has not been met if the following conditions are true:
- The management class has a backup frequency of 2
- The data set was backed up yesterday
- The data set has been changed
- The volume is being processed for backup
However, if the backup frequency is 1 or if the data set had been
backed up the day before yesterday, the data set is backed up.
The default for BACKUP FREQUENCY is 1.
Note: Normally, DFSMShsm processes volumes only if they
were not already processed within the previous 14 hours. A nightly
backup starts over at the beginning. To have DFSMShsm start the backup
with volumes that were not backed up in the previous cycle, set the
backup to a larger number of hours. For a patch command example, refer
to a discussion on the patches to be added to the ARCCMD
xx parmlib member in the
z/OS DFSMShsm Diagnosis.