Using the Automatic Tape Adjustment Facility

The Automatic Tape Resource Adjustment facility optimizes usage of tape or cartridge drives during production batch processing. This facility makes modifications automatically (as opposed to prior versions, in which the user had to manually modify the job definition as necessary). This facility enables Control‑M tape drive resources to be automatically assigned (overriding tape drive resource allocations specified in the RESOURCE parameter of the job scheduling definition).

The Automatic Tape resource Adjustment facility can make the modifications automatically because it tracks usage statistics for each tape resource as it is used.

To implement the Automatic Tape Adjustment facility, perform the following steps:

1. Set the AUTOTAPE parameter to Y (Yes) during Control‑M customization in the INCONTROL Installation and Customization Engine (ICE).
2. Modify the UNITDEF member in the Control‑M PARM library to specify the device numbers of all drives that the facility must control. The format of the definitions is

   devicetype={(}from-to{,from2-to2,...)},DESC=description

   The following table describes the parameters in this command:

   Table 90 UNITDEF Parameters

   Parameter	Description and Values
   devicetype	Type of device being defined. A device type is the set of all drives of the same type. Each tape drive type must be named. The name can be a maximum of 20 characters long, and must not contain embedded blanks. A maximum of 12 tape drive types can be defined. For example, all 3420 tape drives can be named TAPE, and all 3490 cartridges can be called CART.
   	WARNING: The order of the device types in the UNITDEF member must not be changed. Old, obsolete device types should not be deleted, and new device types should only be added at the end of the member.
   from-to	Unit address ranges for each device. The unit address ranges are specified as a series of pairs, the first of which is the starting address and the second of which is the ending address of the device. All addresses must be specified in 4 digits (for example, 0460 and not 460). If one tape drive type consists of more than one unit address range, additional ranges can be specified, separated by commas and enclosed in parentheses.
   description	Descriptive text for the device being defined.

   Example

************************************************************************

 TAPE=0460-046F,DESC=UNITS FOR EXTERNAL TAPES                           

 CARTRIDGE=(0480-0483,0440-0445,0300-031F,0552-0553,0554-0555,          

       0556-0557),DESC=3490 RANGE                                       

************************************************************************

1. Shut down and restart the Control‑M monitor.
2. Exit the IOA online environment and reenter the IOA online environment.

For more information about the turning on the Automatic Tape Adjustment facility, see the chapter on customizing INCONTROL products in the INCONTROL for z/OS Installation Guide: Customizing.