Cache Management › Dynamic Cache Management › Setting Up Dynamic Cache Management in SMS › SMS ACS Routines

SMS ACS Routines

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

If the ACS routines are coded to honor the data class and storage class requested by a user, then no changes are required in the data class or storage class ACS routines. If the ACS routines are set up to automatically override or validate the users' requested data class and storage class, then modifications to these ACS routines will be required.

Because the storage group is assigned by the ACS routines, you must update the storage group ACS to assign the storage group defined for CA Vtape.

The life cycle of the cache LDSs is controlled by CA Vtape. These LDSs do not need to be backed up and should not be migrated. Therefore, you do not need to assign a management class to these LDSs. If the management class ACS routine automatically defines a management class to each allocation or assigns a default, changes may be required.

The sample ACS routine changes in this section assume that:

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

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

IF &DSN = CAVTAPE1.VVE.V*.MM.CACHE OR
   &DSN = CAVTAPE1.VVE.VDATAQ.** OR
   &DSN = CAVTAPE1.VVE.D*.* THEN DO
     SET &DATACLAS = 'DCVTAPE'         
     EXIT CODE(0)
     END 

Note: The data class, DCVTAPE in the sample above, is used by CA Vtape to define its DASD data sets. This data class should not be used in the SMS ACS routines to direct tape mounts to CA Vtape. A separate data class or classes should be defined for intercepting tape mounts. If a DASD data class is used to intercept tape mounts, the tape mounts will be converted by SMS to DASD allocations and the allocations will fail, typically with a SPACE error.

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

• The cache LDSs that contain the application data.
• 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.

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

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

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