DFSMS is a set of IBM software products that automatically manages your data from the point where you create it until you no longer need it (or move it to a less costly device). As IBM’s approach to automating the management of storage resources, it consists of these five components:
- DFSMSdfp (Data Facility Product), the biggest and only non-optional component on this list, provides the data, storage, program, and device management. It includes the following subcomponents: Extended Remote Copy (XRC), Peer-to-Peer Remote Copy (PPRC), Network File System (NFS), FlashCopy, SnapShot, and Concurrent Copy.
- DFSMSdss (Data Set Services) is the high-speed data mover used, among other things, to copy data from disk to disk or disk to tape.
- DFSMShsm (Hierarchical Storage Manager) quickly and automatically assists in moving data to less costly devices.
- DFSMSrmm (Removable Media Manager) helps deal with removable media.
- DFSMStvs (Transactional VSAM Services) covers data integrity for shared VSAM by batch and CICS.
With DB2 10, SMS will manage and control all new catalog changes, all the conversions to universal table spaces and all new catalog and directory indexes and table spaces. If you’ve been putting off taking advantage of DFSMS with DB2, it’s time to get comfortable with it. All the new indexes and table spaces being added in DB2 10 will also use Extended Addressability (EA). If DB2 detects that the catalog and directory aren’t in an SMS-compliant environment, an abend will occur.
The migration job, DSNTIJSS, provides the necessary DFSMS classes for customers currently not using DFSMS. The environment created by DSNTIJSS is only for the DB2 catalog and DB2 directory objects. No other DB2 data sets are covered. DSNTIJSS must be completed before the installation/migration jobs, DSNTIJTC or DSNTIJEN, are executed.
Start working with your storage management group, or at least warn them about what’s just over the horizon. If you’ve been dodging using DFSMS for all these years, dodge no longer. Learn more in these publications:
- z/OS V1R10.0-V1R11.0 DFSMS Introduction
- z/OS V1R11.0 DFSMS Implementing System-Managed Storage
- z/OS V1R12.0 DFSMShsm Storage Administration Guide
- z/OS V1R12.0 DFSMSdfp Storage Administration Reference
- z/OS V1R12.0 DFSMSdss Storage Administration Guide
DB2 10 doesn’t force you to move to DFSMS alone. When installing (or migrating) to DB2 10, the installation panels will help you specify the correct SMS information DB2 10 needs for the catalog, directory, and their indexes. DB2 10 provides entries on the installation/migration panel, DSNTIPA2, for specifying the SMS data classes, management classes, and storage classes for the catalog, directory, and catalog/directory indexes similar to what’s currently available on the DB2 9 panel, DSNTIPA3. However, unlike DB2 9, DB2 10 also provides three new DSNZPARM parameters for each catalog and directory (CATDDACL, CATDMGCL, and CATDSTCL on the DSN6SPRM macro), and the catalog and directory indexes (CATXDACL, CATXMGCL, and CATXSTCL also on the DSN6SPRM macro).
Before populating the fields on the installation/migration panel, your storage administrator should provide you with the SMS data classes, management classes, storage classes, and any necessary SMS Automatic Class Selection (ACS) routines. Make sure SMS is configured to allocate all the DB2 catalog and directory data sets in extended format and use extended addressability.
DSNTIJTC migrates the DB2 catalog and directory from DB2 9 or Version 8 to DB2. It will also create any new catalog objects (new directory objects are created by DSNTIJEN), add columns to existing catalog tables, and create and update indexes on the catalog tables for DB2 10. DSNTIJTC creates the IBM-supplied indexes. These changes could require some of the IBM-supplied catalog indexes to be rebuilt to remove the advisory rebuild-pending status. Change data capture is also disabled as part of the migration to DB2 10 CM. If you plan to use change data capture with SYSROUTINES catalog table, it must be enabled. All the aforementioned catalog and directory changes are completed before or as part of the upgrade to DB2 CM.
DB2 Catalog Links
DB2 10 is making significant changes to the DB2 catalog and directory. To appreciate where the catalog is heading, consider where it is today by looking at DB2 catalog links. This feature is best explained with an example using catalog table space SYSDBASE.