Parameters

XTYPE=

Indicates a 1- to 8-character name which matches the first operand in the XTYPE parameter on a DEVICE statement. The XTYPE parameter associates this statement with a specific device definition indicated on a DEVICE statement. The XTYPE parameter must always precede the NAMES or POOLNAMS parameters.

Devices within a specific XTYPE should have compatible characteristics. If the XTYPE parameter is the same on two different SETNAME statements, the NAMES parameter on the two statements must be different.

NAMES=

Identifies all names (user-assigned and device type) used to refer to the device defined in the associated DEVICE statement. The NAMES parameter indicates what names are used to specify devices in the UNIT parameter of any DD statements. Each name must also have been indicated during system installation. Note that device type names must be included if allocation of cataloged data sets that are on these device types is done by JES3 even though the devices are not directly referred to in the UNIT parameter of a DD statement. For example, if UNIT=2314 is specified, 2314 must be defined as a name.

By organizing names, the system programmer can identify unit allocation requirements (including specific device attributes, such as tapes with a special density) and can balance the load across available channel paths.

If the same names are specified in the NAMES parameter, but in a different order for the same XTYPE, an order of preference for device selection is created for requests that require volume mounting. (See the first example.) If an order of preference is created, it must be the same for both JES3 and MVS™.

Note: If you have replaced one device type on your system with a different device type and the resource is still referred to using the old device name (for example, in catalog entries), do not remove the name of the old device type from the NAMES parameter. Leave it in and add the name of the new device type.

POOLNAMS=

Specifies the 1- to 8-character name(s) that may be used only for dedicating devices to job class groups or dependent job control jobs. The pool names specified may be used in the DEVPOOL parameter of the GROUP statement , the //*NET statement, or both. These names may not be used in the UNIT parameter of the DD statement.

Note:

The MVS generic names must be included if cataloged data sets residing on these types are to be allocated by JES3, even though direct reference to them is not made in the UNIT parameter of their DD statements.
There must be a SETNAME statement for the IBM® generated esoteric names SYSALLDA, SYS3480R, and SYS348XR in the initialization deck if these values are to be coded or defaulted for allocations which are to be JES3 manages.
For more information about IBM generated esoteric names, see z/OS HCD User's Guide.
If a dynamic allocation is made for a time-sharing user and a UNIT parameter is not included in the DD statement, the UNIT parameter is obtained from the time-sharing user attribute data set (UADS). If the UADS does not contain a UNIT parameter, or if the user is not a time-sharing user, an MVS default of SYSALLDA (that is, all direct access devices) is assumed.
It is recommended that a default UNIT parameter value be defined in the UADS and that all dynamic allocations specify a UNIT parameter. Otherwise, if JES3 is to manage the dynamic allocations that do not have a UNIT parameter, the MVS default UNIT value (SYSALLDA) must be included in SETNAMES for all DA device types.