System Components and Execution › CA TLMS Major Features › External Data Manager (EDM) Processing

External Data Manager (EDM) Processing

CA TLMS provides EDM support by assigning volume ownership to the EDM and giving it full control of the contents. The EDM is identified by matching information in CTOEDM00 (the owner table). There may be multiple EDMs, each having a separate EDM ID, and multiple sets of definitions for each EDM ID. CA TLMS applies volume ownership by placing the EDM ID in the OWNER field of the volume base record.

This option relates DSN, job name and program name criteria to an EDM ID. CA TLMS assigns the EDM ID to each transaction with matching criteria. The transaction is said to be "from an EDM."

CA TLMS processes EDM (or owned) tapes as follows:

• Each tape created from an EDM is recorded in the VMF as volume 1 of 1, with the DSN of the first data set on that tape. This is done regardless of the number of tapes and/or data sets actually related to it.
• CA TLMS will ensure that only files from matching EDM IDs are written on a tape and that files from EDMs are not written on non-EDM tapes.
• The EDM is responsible for the contents of its tapes. CA TLMS will allow the EDM to write or overwrite any tape it owns and has specifically requested. This permits the EDM to reuse a tape without scratching it.
• Only the EDM can scratch a tape it owns. Therefore, each EDM is responsible for scratching tapes it no longer needs. This may be done using DISP=(OLD,DELETE) or a manual transaction to scratch.

You may use the Tape Retention System (TRS) to control movement of EDM tapes. No special coding is required, because EDM ownership is recorded in the VMF. EDM tapes may be processed separately or in a group with other tapes. Since only the EDM can scratch its tapes, it is a good practice to use type 7 (manual retention) for the last location of EDM tapes. TRS will not scratch the tapes no matter what RMF rules are coded, but it will issue error messages showing the tape was retained for EDM.

Tape pools defined for EDMs using the CTOEDM00 member are pointed to by the EDM= option in TLMSIPO.

Dynamic VMF Extend

CA TLMS lets you switch to a new VMF while still processing tapes. The new VMF must be large enough to contain all the active records that are in the old VMF. This new VMF can reside on the same volume or a different volume than the original VMF.

CATVMFX controls the dynamic VMF extend process. During the extend process, all TLMSs add a new VMF and perform synchronous updates to both VMFs while records from the old VMF are copied to the new VMF. After all active records are copied, CATVMFX creates a VMF alias pointing to the new VMF and all batch and online tape activity references the new VMF using this alias. After all jobs referencing the old VMF during the extend process are complete, all TLMSs will drop the old VMF, marking the end of this process.

Note: The old and new VMFs are updated synchronously during the extend process. You do not need to stop batch and online-tape activity. All jobs, referencing either the old or the new VMF, can run until finished.