Setting Up the Enhanced Data Integrity Function

About this task

Before you begin: z/OS DFSMS V1R5 is provided with the data integrity function inactive. Usually, a system programmer would set up the data integrity function. When you activate the data integrity function, multiple users no longer have concurrent output or update access to a sequential data set on DASD.

Determine whether your system requires the data integrity function. Can the applications allow concurrent access to sequential data sets for output or update, and still maintain data integrity?

Perform the following steps to set up data integrity processing for your system.

Procedure

Create a new SYS1.PARMLIB member, IFGPSEDI. The IFGPSEDI member contains the MODE variable and an optional list of data set names to be excluded from data integrity processing. IFGPSEDI can be in any data set in the SYS1.PARMLIB concatenation.
_______________________________________________________________
Set IFGPSEDI to one of the following MODE values. MODE must start in the first column of the first record.
MODE(WARN)

The program issues a warning message when an application attempts to open for output a shared data set that is already open, but it allows the current open to continue. This situation is called a data integrity violation.

MODE(ENFORCE)

The program abends when a data integrity violation occurs.

MODE(DISABLE)

Data integrity processing is disabled.

_______________________________________________________________
Use DSN(data_set_name) to specify which data sets, if any, to include in the exclude list in the IFGPSEDI member.
The data set name can be a partially qualified or fully-qualified name. The data set name also can contain an asterisk or percent sign.

When you specify MODE(WARN) or MODE(ENFORCE), data integrity processing bypasses data sets that are in the exclude list in IFGPSEDI. The exclude list excludes all data sets with that same name in the system. (If the data set is not system managed, multiple data sets with the same name could exist on different volumes, so they would be excluded.)

_______________________________________________________________
Once you have created the IFGPSEDI member, activate data integrity processing by IPLing the system or starting the IFGEDI task. The IFGEDI task builds a data integrity table from the data in IFGPSEDI. _______________________________________________________________

Results

Result: After you activate data integrity processing, message IEC983I displays. The system issues this message during IPL or after you start the IFGEDI task. This message indicates whether data integrity processing is active and the mode (WARN, ENFORCE, or DISABLE).

If the SYS1.PARMLIB member, IFGPSEDI does not exist or it specifies MODE(DISABLE), data integrity processing is not active and conventional processing for shared sequential data sets continues.