You can use the EDG_EXIT100 installation exit to set the retention method to be used for new tape data sets. When you create a new tape volume set, or rewrite an existing set from the first file you can override the system default retention method.

1. Define the system default retention method. Refer to Parmlib Member EDGRMMxx OPTION Command
2. Define the DFSMSrmm default and maximum retention periods. OPTION RETPD MAXRETPD
3. Update the sample EDGUX100 exit module based on your retention requirements:
   1. Copy the sample EDGUX100 exit module and use the copy as a base for your exit module.
   2. Update the exit module. Perform your processing only when the PL100_CAN_RETMET bit is set to B'1'. Set PL100_RETENTIONMETHOD to the value required, and ensure the PL100_SET_RETMET bit is set to B'1'. If you do not set a retention method, the system default retention method is used.
   3. Make any other changes required, such as setting or clearing the EXPDT.
   The sample EDGUX100 exit module includes an example of setting the retention method. To use the sample EDGUX100 exit module for this function, modify the table as shown in Figure 1. The order in which the table entries are listed is important because the exit scans the table until it finds the first entry where the job name, data set name and program name masks match the current request. You can change the priority of matching by changing the order of the table entries.

   Figure 1. Sample retention method selection table

   RMTAB    DS    0F                  START OF RM TABLE           
            SPACE 1                                               
            DC    CL8'*'              JOBNAME                     
            DC    CL44'RMMUSER.RMVRSEL.*' DATA SET NAME           
            DC    CL8'*'              PROGRAM NAME                
            DC    AL1(PL100_RM_VRSEL) RETENTION METHOD VRSEL      
            DC    XL3'00'             RESERVED                    
            SPACE 1                                               
            DC    CL8'*'              JOBNAME                     
            DC    CL44'RMMUSER.RMEXPDT.*' DATA SET NAME           
            DC    CL8'*'              PROGRAM NAME                
            DC    AL1(PL100_RM_EXPDT) RETENTION METHOD EXPDT      
            DC    XL3'00'             RESERVED                    
            SPACE 1                                               
            DC    CL8'RM END'         END OF RM TABLE MARKER

   The RMTAB table contains:

   jobname

   One-to-eight alphanumeric or national characters, including % and *.

   • The character % can be used to ignore a positional character in the job name.
   • The character * can be used to ignore all remaining characters in the job name. A jobname of * means that the entry applies to all jobs.

   data set name

   Can be up to forty-four characters, following z/OS data set naming conventions, including % and *.

   • The character % can be used to ignore a positional character in the data set name.
   • The character * can be used to ignore all remaining characters in the data set name. A data set name of * means that the entry applies to all data sets. The use of the character * is not the same as in the generic data set names supported by DFSMSrmm for vital records specifications and search data set masks. Here the * works like the characters *.* might in a generic data set name mask.

   program name

   A value up to eight alphanumeric characters, including % and *.

   • The character % can be used to ignore a positional character in the program name.
   • The character * can be used to ignore all remaining characters in the program name. A program name of * means that the entry applies to all programs.

   retention method

   One of:

   • PL100_RM_VRSEL to assign the retention method VRSEL
   • PL100_RM_EXPDT to assign the retention method EXPDT

4. Activate the sample EDGUX100 exit module. See Installing the EDGUX100 default exit routine for information about building an SMP/E USERMOD to apply the updated source code for EDGUX100 so that it supersedes any old EDGUX100 USERMODs. Include the necessary JCLIN statements as shown in Figure 1.
5. When you write new tape data sets, DFSMSrmm calls your installation exit and saves the resultant retention method into the volume record and propagates it to all future volumes added to the volume set. Use LISTVOLUME to verify that the correct retention method is recorded. Run inventory management to verify that the applied retention method is used for your new data.