SAP Note 19003 - Offline redo log backup on several tapes

Symptom:

More offline redo log files are created during the day than can be saved on one tape.
BRARCHIVE then has to be restarted, and a new tape must be inserted, excluding the possibility of an unsupervised backup. The problem can occur, for example, when a great deal of night background processing occurs and the total size of the created offline redo log files exceeds the total capacity of the archive directory plus one tape.
While this situation is rare, it cannot be discounted completely.

Cause and prerequisites

BRARCHIVE can only write one tape to capacity, and does not support subsequent tapes.

Solution
Use a shell script to start BRARCHIVE in serial on several tape stations.
To do this, you need several init.sap profiles that define different tape stations in the parameters tape_address and tape_address_rew, for example:

initC11.sap.arch1
----------------
...
tape_address = /dev/rmt/0mn
tape_address_rew = /dev/rmt/0m
...

initC11.sap.arch2
-----------------
...
tape_address = /dev/rmt/1mn
tape_address_rew = /dev/rmt/1m
...

Sample shell script:
--------------------
brarchive -p initC11.sap.arch1 -v scratch -f -c
brarchive -p initC11.sap.arch2 -v scratch -f -c

In the above example, the first BRARCHIVE will terminate once it has written the tape in the first tape station to capacity, and the second BRARCHIVE, which uses the second tape station, will start automatically. A prerequisite for this is that free tapes be inserted in the tape stations. You can also leave out the "-v scratch" option if you know which tapes will be requested by the automatic tape management (query: brarchive -q).