CA TLMS - release the auxiliary records

Products

• TLMS Tape Management

Issue/Introduction

When and how the auxiliary records are released ?

Environment

Release : 14.0

Component : TLMS Tape Management

Resolution

The auxiliary record can be released during the CATTRS process :

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.

When TLMS  scratches a tape volume it normally retains the information on that tape until it is reused. This information can be used for reference or to unscratch the tape volume. 

TLMS  keeps information for each file and volume. For modern high capacity tapes, 

TLMS  may be retaining a large number of records containing information on scratch tapes. Some robotic devices use tapes in a circular fashion where a tape is not reused until all of the tapes have been used.

To free records used for unneeded information on scratch tapes, specify the following control card:

 

FREE-SCRATCH-CHAIN-AFTER DAYS=nnnn

 

nnnn

Specifies the number of days after a volume is scratched.

Before the scratch chains are freed all of the following conditions must be met:

• The volume must have been scratched for more than nnnn 
• TRS must have processed the volume and moved it to the Data Center.
• The volume must have a multi-volume or multi-data set chain in the VMF.
• The DSN must be non-blank.
• To prevent excessive overhead, this feature frees only 200 chains per TRS run.
• This feature does not affect scratch tapes that do not have multi-volume or multi-file chains because no records can be freed.

 more information can be found: CATTRS - FREE-SCRATCH-CHAIN-AFTER

 

AND in function the value coded for the BRKCHN parameter loaded during the start of TLMS:

BRKCHN System Option -- Break Volume/Data Set Chains

Use the BRKCHN when you want to break the relationship between multivolume chains at OPEN, CLOSE, or when you the scratch a tape. 

 BRKCHN=[OPEN|CLOSE|SCRATCH] 

OPEN (Default) Specifies that a chain is broken when one of the volumes in the original chain is opened for output. Each volume within the chain becomes a single volume and all fields (except tape history) in the associated VMF records are reset.

CLOSE Specifies that chains are broken when the first data set is closed on a volume. This option is supplied for compatibility with earlier releases. We recommend that this option be used in special circumstances only. The chains are broken at OPEN, regardless of this option being specified.

SCRATCH Specifies that all chains are broken and previous information (except tape history) is reset. If a tape is scratched in error, the information and chaining sequence is erased; therefore, exercise caution when considering this selection