To prepare your installation for system-managed tape, you need to include the following major tasks in a conversion plan:

1. Evaluate job dependencies on the JCL UNIT parameter.
   Consider the implications of certain SMS restrictions on JCL UNIT parameter usage. The device used to satisfy an allocation request is selected from device pool information associated with a given tape library. Because of this, the following situations occur:

   • Demand allocation is not supported. For example, UNIT=520 (where 520 is the address of a 3490 drive) is not valid if SMSHONOR is not coded.
   • The UNIT keyword is not actually used to select a tape device. However, this keyword is available to your ACS routines to use for filtering purposes.
   • Devices requested using unit affinity, such as UNIT=AFF=DD1, are honored only if the volumes reside in the same tape library and use compatible devices.

   Except for demand allocation, JCL changes are not required to use tape library dataservers.

2. Define the tape environment to z/OS®.

   Tape drives in an automated or manual tape library are defined using the hardware configuration definition. A library ID defined to the ISMF library application links the system-managed tape library definition to the tape library. The library ID is defined to HCD by specifying the LIBRARY-ID and LIBPORT-ID parameters for each library device. Both the LIBRARY-ID and the LIBPORT-ID are arbitrary numbers. The HCD help text for the LIBRARY-ID and LIBPORT-ID parameters explain how you can obtain the IDs.

3. Define OAM.

   Tape library support uses OAM to define system-managed tape libraries and volumes. You need to update various PARMLIB members to define OAM.

4. Define the classes, storage groups, and associated ACS routines.

   You can use the established data classes when you implemented tape mount management to control the categories of tape data sets that are allocated on system-managed tape volumes. You can also define special classes for managing DFSMShsm-owned volumes in a tape library, and for tapes that hold objects.

   If your tape management system supports the pre-ACS interface, you can use the information available to you (for example, the scratch pool and policy in the MSPOOL and MSPOLICY variables) when coding the ACS routines to direct tape allocations to specific libraries, to a DASD pool (for tape mount management), or to keep them outside of the system-managed environment.

   Tape storage groups, defined under ISMF, associate the tape libraries to tape storage groups. A scratch tape volume becomes system-managed when it is entered into a system-managed library. A scratch tape becomes part of a storage group when a system-managed data set or object is allocated on the volume. System-managed volumes are assigned to a tape storage group. Tapes that contain objects also belong to either an object or an object backup storage group.

   After you define a tape storage group, you must set the status for the storage group on each system that uses the tape library dataserver.

5. Create the tape configuration database.

   You must define one general volume catalog. One or more specific volume catalogs can also be defined based on your installation's requirements. The collection of your installation's general and specific volume catalogs is the tape configuration database.

   DFSMS determines which catalog to update based on the first character of the volume serial number. Naming conventions for volume serial numbers can help you balance catalog update activities.

   You can use access method services to define volume catalogs and use standard ICF support for backup and recovery.

6. Define the tape libraries.

   Before you define your tape libraries, make sure that update authority for your tape configuration database is restricted to storage administrators.

   Create a logical tape library definition for each grouping of tape volumes associated with a collection of tape devices. This definition becomes part of your active SMS configuration and a library entry is generated in the tape configuration database. It is created using a new ISMF application that is invoked from the Library Management application. ISMF also allows you to redefine the tape library from information in the tape configuration database.

7. Create any system-managed tape exits, if required.

   There are several DFSMSdfp installation exits that you can use specifically with tape library dataservers. DFSMSrmm also uses selected DFSMSdfp exits to manage some of its tape processing.

8. Translate and validate the new SMS configuration.

   Use the same translation and validation steps that you follow for most other SMS configurations. The new configuration is considered valid if all tape libraries associated with tape storage groups exist for SMS.

9. Test the new SMS configuration.

   Use ISMF to write and run test cases to verify that your new, or modified, ACS routines properly assign the new tape classes and storage groups.

10. Activate the new SMS configuration.

    Activate the new system-managed tape configuration as you would other SMS configurations.

11. Start OAM.

    Place the start-up PROC for OAM in PROCLIB. You must have OAM running on all processors that will use the automated libraries.

12. Enter volumes in the tape library dataserver.

    If you are using the automated tape library dataserver, add your tape cartridges to the dataserver before you begin testing allocations.

13. If you are using a manual tape library, use the Manual Cartridge Entry programming interface or the library enter console command.
14. Test library usage for SMS tape allocations.

    Perform selective allocations to check library usage before converting the rest of your tape data to system-management.

15. Put the tape library into production.

    Consider converting your tape data to system management by category of data, using the following suggested order:

    1. Large temporary data sets
    2. DFSMShsm-owned volumes
    3. Offsite volumes
    4. Active volumes
    5. Backup volumes

Normal SMS processing ignores the UNIT parameter. So, JCL or dynamic allocations could be specifying unit names that no longer exist in the system. However, if the new keyword SMSHONOR (in JCL) or DALSMSHR (for dynamic allocations) is coded along with a valid device name or esoteric name, device allocation will attempt to allocate to the devices that are common to the UNIT and device pools selected by SMS.