Sequential Migration to Tape › General Information › Expiration Dates Assigned to Data Sets on Tape

Expiration Dates Assigned to Data Sets on Tape

For every data set on tape, the header label contains the expiration date field just as the format-1 DSCB does for every data set on disk. As each data set is migrated from disk to tape, a decision is made regarding what value to supply for its expiration date on tape. Sysparms MIGEXPDT and MIGFXPDT control this decision.

The default value of N for MIGEXPDT causes each expiration date on disk (from the format-1 DSCB) to be copied forward to the tape, unless its value is all zeros. If it is zeros, CA Disk will substitute the expiration date (or retention period) that you supply in the MIGRATE dd statement. If you specify a value of Y for MIGEXPDT, the JCL-supplied date will be substituted for every data set being migrated. (If a duplicate copy tape is being created, the expiration dates for it are created in the same manner but the date from the MIGRATEC dd statement is used instead, and it can be different from the primary tape.)

For more information, see the section Year 2000 Considerations in the chapter "General Information."

You should also consider that tape management systems often regard tapes created with data set expiration dates equal to the current date as being work tapes, and therefore won't log the data sets in the tape management catalog. To prevent this, sysparm MIGFXPDT is provided. Its default value of Y causes CA Disk to add one day to the expiration date whenever it finds an expiration date equal to the current date.