Tape Consolidation

With ERO processing, it is possible for
View
backup tapes to contain reports that expire at different times. For any particular tape, there can be one report that has ERO retention criteria of seven years, but other reports on the tape may have expired. The space occupied by these reports should be reused.
view
With ERO processing, it is possible for
View
backup tapes to contain reports that expire at different times. For any particular tape, there can be one report that has ERO retention criteria of seven years, but other reports on the tape may have expired. The space occupied by these reports should be reused.
The SARPAC tape consolidation utility is provided with ERO to consolidate backup tapes. SARPAC copies current reports (retained by
View
) and bypasses expired reports. The first
View
backup cycle (standard or interim) following a SARPAC consolidation uncatalogs the input tapes that are no longer needed.
You can use SYSIN DD statements to process the following:
  • All backup tapes for the database
  • A particular backup tape (by
    View
    tape sequence number)
  • A range of tapes
  • A particular tape storage group
You can use storage groups to put reports with the same retention on the same tape, thereby minimizing the need for consolidation.
Note:
For information about tape storage groups, see
Initialization Parameters
.
The ERO initialization parameters PTHRESH, PMXTAPES, and PMXYEARS control which tapes are consolidated by SARPAC. This table provides a description of each of these parameters:
  • PTHRESH
    Lets you specify a threshold value.
    For example, only consolidate tapes that are 55 percent unused.
  • PMXTAPES
    Lets you limit the SARPAC run by specifying the number of tapes that will be processed.
  • PMXYEARS
    Lets you specify how long a tape can exist before it is automatically consolidated, an important function because tapes tend to have I/O problems as they age.
You can use the SYSIN statements to specify which tapes to use for input. Additionally, you can modify the SARPACUX user exit to select input tapes based on user-defined criteria.
SARPAC mounts its input tapes directly. SARPAC does not use the expanded access server for tape and robotics to mount input tapes.