When a tape is scratched, the volume and dataset chaining records remain intact until one of the volumes is reused. At that time, the volume series is cleared and the chaining records are returned to the chaining free pool for reuse. Some robotic devices use tapes in a circular fashion where a tape is not reused until all the tape pool has been used. This can cause volume chains to spend more time in the used chain pool when they could be the free-chain pool within CA-TLMS.
This could cause a CA TLMS volume chaining shortage.
Free Scratch Chains After a Set Number of Days
You can use a SYSIN control statement to use TRS to free unneeded records from the VMF.
To free records used for unneeded information on scratch tapes, specify the following control card:
Before the scratch chains are freed all of the following conditions must be met:
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