DFSMSrmm ACS Support
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Starting with DFSMSrmm V2.10, you can use your SMS ACS routines to assign a VRS management class and to select a specific scratch pool. To enable this function, you update your SMS environment to allow a management class to be used in place of the VRS management value assigned in the EDGUX100 user exit, and a storage group name to be used as a scratch pool name.
To enable DFSMSrmm ACS support, you must have the SMS subsystem active and have a valid SMS configuration.
With OS/390 V2R10 or higher, SMS ACS routines are always called by DFSMSrmm if you have a tape mount outside a SMS managed tape library.
ACS processing for non-system managed tapes can be tailored by the PARMLIB member EDGRMMxx OPTION subparameters PREACS and SMSACS. In the following sections are the operands of the EDGRMMxx OPTION subparameters.
PREACS
Specify the PREACS operand to control whether DFSMSrmm-supplied values and EDGUX100 installation exit-supplied values are input to SMS pre-ACS processing:
The scratch pooling and policy assignment rules are per default coded in EDGUX100 user exit. You can move your decisions to the SMS ACS routines, where you can use ACS input variables as a base for management class and storage group assignment:
Use ACS routines for scratch pooling based on tape storage group names. Using ACS processing to set a storage group name overrides all other pool selection methods. DFSMSrmm provides support for non-system-managed tape and for system-managed manual tape libraries. This support enables pooling at the individual volume level. You assign a storage group name to each volume by using DFSMSrmm TSO subcommands or by using pooling information that you define with the DFSMSrmm EDGRMMxx PARMLIB VLPOOL command. DFSMSrmm calls ACS routines passing environment information, including the pool identified by DFSMSrmm system-based pooling. The ACS routine can optionally set a storage group name, which overrides the DFSMSrmm system-based pool.
ACS support for non-system managed volumes
In a non-system-managed library, DFSMSrmm supports SMS ACS routines in different ways:
Use ACS routines for scratch pooling based on tape storage group names. Using ACS processing to set a storage group name overrides all other pool selection methods. DFSMSrmm provides support for non-system-managed tape and for system-managed manual tape libraries. This support enables pooling at the individual volume level. You assign a storage group name to each volume by using DFSMSrmm TSO subcommands, or by using pooling information, which you define with the DFSMSrmm EDGRMMxx PARMLIB VLPOOL command. DFSMSrmm calls ACS routines passing environment information, including the pool identified by DFSMSrmm system-based pooling. The ACS routines can optionally set a storage group name, which overrides the DFSMSrmm system-based pool.
A non-system-managed tape library is all the volumes, shelves, and drives that are not in an automated tape library dataserver or manual tape library. You might know this as the traditional tape library in a data center or as an automated environment that is not system-managed. DFSMSrmm provides complete tape management functions for the volumes and shelves in this traditional tape library.
All tape media and drives supported by z/OS are supported in this environment. Use DFSMSrmm to fully manage all types of tapes in a non-system-managed tape library, including 3420 reels, 3480, 3490, 3590, and 3592 cartridge system tapes.
You can also use DFSMSrmm to manage volumes in any automated tape library that has special software including an IBM Tape Library Data server that is managed using Basic Tape Library Support (BTLS).
Most non-IBM libraries do not provide support for system-managed tape, so we consider them to be the traditional tape libraries.
The IBM direction is to replace DFSMSrmm exit function with an alternative, either SMS policy or PARMLIB option.
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