Setting Up SMS › SMS Definitions › DFSMS ACS Routines

DFSMS ACS Routines

For Dynamic Cache Management, CA Vtape dynamically allocates a cache data set when needed. The dynamic allocation is requested using the data class and storage class that is defined exclusively for CA Vtape.

If the ACS routines are coded to honor the data class and storage class that a user requests, then no changes are required in the data class or storage class ACS routines. If you set up the ACS routines to override or validate the users' requested data class and storage class automatically, then you modify these ACS routines.

If you defined a new storage group for CA Vtape, then update the storage group ACS to assign the new storage group.

The sample ACS routine changes in this section assume that:

• The CA Vtape DSN prefix that is defined during customization is the default value of CAVTAPE1.
• The data class that is defined for CA Vtape is DCVTAPE.
• The storage class that is defined for CA Vtape is SCVTAPE.
• The storage group that is defined for CA Vtape is SGVTAPE.

The following sample shows a data class ACS change based on the previous assumptions:

IF &DSN = CAVTAPE1.VVE.D*.T*.LIB* OR
   &DSN = CAVTAPE1.VVE.VDATAQ.** OR
   &DSN = CAVTAPE1.VVE.D*.* THEN DO
     SET &DATACLAS = 'DCVTAPE'         
     EXIT CODE(0)
     END 

Note: CA Vtape uses the data class (DCVTAPE in the example) to define its DASD data sets. Do not use this data class in the SMS ACS routines to direct tape mounts to CA Vtape. Define a separate data class or classes to intercept tape mounts. If you use a DASD data class to intercept tape mounts, SMS converts the tape mounts to DASD allocations. The allocations then fail, typically with a SPACE error.

The three data set naming patterns being checked for in the sample are as follows:

• The Tasklib loadlib where the qualifier that starts with a D is following by the date, the qualifier that starts with a T is followed by the time, and the last qualifier is followed by the last digit of the Subsystem number (1-8).
• The data set which backs up a data space communication area, saving the stored information across restarts.
• The work data sets allocated for each Virtual Device where the qualifier that starts with a D is followed by the device number and the last qualifier is the system name. These data sets are 8 MBs in size and one is allocated for each online Virtual Device.

Since all the data set names start with CAVTAPE1.VVE, if you do not need to put these data sets in different storage classes or groups, you could code a single pattern of CAVTAPE1.VVE.** in the data class ACS routine.

The following sample shows a storage class ACS change that is based on the previous assumptions:

IF &DATACLAS = 'DCVTAPE' THEN DO
     SET &STORCLAS = 'SCVTAPE'         
     EXIT CODE(0)
     END 

The following sample shows a storage group ACS change that is based on the previous assumptions::

IF &STORCLAS = 'SCVTAPE' THEN DO
     SET &STORGRP = 'SGVTAPE'         
     EXIT CODE(0)
     END 

The following sample shows a management class ACS change that is based on the previous assumptions::

IF &STORCLAS = 'SCVTAPE' THEN DO
     SET &MGMTCLAS = ''         
     EXIT CODE(0)
     END 

Once these changes are activated in DFSMS, test them by allocating a test data set that matches the naming standard of any of these data sets and uses the CA Vtape data class and storage class. After the data set is allocated, execute an IDCAMS LISTCAT to verify that the appropriate DFSMS constructs were assigned to the data set and it was allocated on a DASD volume in the correct storage group.