Enhancements to Existing Features › Expanded TMC Capacity

Expanded TMC Capacity

Users who require more than 16.9 million combined volume and DSNB records may now define the CA 1 Tape Management Catalog (TMC) as a Large Sequential data set (DSNTYPE=LARGE). When defined as DSNTYPE=LARGE, the capacity of the TMC is increased from the previous limit of 4,369 cylinders to support up to 46 million volumes and 100 million DSNBs.

The CA 1 Programs that use BDAM access routines to read and update TMC records have been changed to use EXCP instead of BDAM. If you implement the Large Sequential format TMC you must do the following:

• Reassemble any routines that access the TMC with the CAI.CTAPMAC macro library.
• Define a new TMC with the DSNTYPE=LARGE parameter and either copy the data using standard utilities or run the CA 1 TMSXTEND utility.

You can convert back to the old format TMC using these utilities if required as long as the number of records does not exceed the capacity of the old format.

Note: This feature is optional. We recommend that only sites nearing the current capacity limits should convert the TMC to Large Sequential format.