To prepare your installation for system-managed tape, you need
to include the following major tasks in a conversion plan:
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Activate the new SMS configuration.
Activate the new system-managed
tape configuration as you would other SMS configurations.
- 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.
- 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.
- If you are using a manual tape library, use the Manual Cartridge
Entry programming interface or the library enter console command.
- 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.
- Put the tape library into production.
Consider converting
your tape data to system management by category of data, using the
following suggested order:
- Large temporary data sets
- DFSMShsm-owned volumes
- Offsite volumes
- Active volumes
- 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.