Using Alternate Backup Sets
Introduction
What is an alternate backup set? You can use an alternate backup set when you want to save several backup sets to the same tape. By specifying an alternate backup set, you can append one or more backup sets to the end of the volume. As tape technology advances, tapes can hold increasing amounts of data. Using Robot/SAVE’s alternate backup set feature for your saves helps you decrease the number of tape volumes used, while still providing you with the same tape management and restoration information you’ve come to depend on. You also can use alternate backup sets with Automated Media Libraries (AMLs).
Use these helpful tips to help you start using alternate backup sets.
Tips for Using Alternate Backup Sets
Tip #1
When you use alternate backup sets, you must use the same rotation in each set. The backup sets can be in different classes or in the same class. However, you must run the same rotation for each set.
Example
Backup Class: TESTALTERNATE
| Backup Set | Name | Sequence | Save | Rotation |
| TESTA | parent set name | 10 | 0/00/00 | A |
| TESTB | first child set name | 200 | 0/00/00 | A |
| TESTC | second child set name | 300 | 0/00/00 | A |
Backup Class: TESTALTER1
| Backup Set | Name | Sequence | Save | Rotation |
| TESTA | parent set name | 10 | 0/00/00 | A |
| TESTB | first child set name | 200 | 0/00/00 | A |
| TESTC | second child set name | 300 | 0/00/00 | A |
Tip#2
All child sets must point to the parent set. You specify the name of the parent backup set on the Extended Backup Set Maintenance panel.
Tip #3
The alternate backup sets can be from different backup classes.
Tip #4
The parent backup set tracks all volume information, such as, move locations, volumes used, object history, expiration dates, and next usage date.
Tip #5
If you use an Automated Media Library (AML), bar code labels must match internal tape volume IDs.
Tip #6
When you use alternate backup sets, the tape remains loaded after the save has completed. You can specify an after-backup program on the child backup set to call a program to run the command CHKTAP ENDOPT(*UNLOAD).
Note: This does not apply to AMLs.
Tip #7
If the backup sets are all from the same backup class, Robot/SAVE automatically updates the rotation code for any backup set that was skipped to the rotation code of the current set. This process is called leveling. When you use alternate backup sets, the rotation code is leveled based on the rotation code of the parent set. See the Robot/SAVE User Guide for more information on leveling.
Updated July 7, 2002