Defining pools in parmlib member EDGRMMxx

You must define any pool that you plan to use with DFSMSrmm in the parmlib member EDGRMMxx using the VLPOOL command. This applies to pools used by DFSMSrmm pooling and by the EDG_EXIT100 exit. See Defining pools: VLPOOL for information on using VLPOOL command in the parmlib member EDGRMMxx. Also consider shelf space and whether volumes are to be segregated based on media names for any scratch pooling method you use.

Define at least one pool using the VLPOOL command in the DFSMSrmm parmlib member. Use the pools to assign a media name for shelf space and volumes based on a prefix. Define a default pool to ensure that volumes and racks that do not match to a more specific VLPOOL are added with the correct media name and pool name.

Figure 1 shows a VLPOOL command example of the default pool that DFSMSrmm assigns if you do not specify any VLPOOL commands. This default pool includes all shelf locations, all volumes in those shelf locations, and all volumes with no defined shelf location.

Figure 1. Default VLPOOL command

 VLPOOL RACF(N) TYPE(S) -
   EXPDTCHECK(O) MEDIANAME(parmlib_default_medianame) -
   DESCRIPTION('DEFAULT POOL') PREFIX(*)

In the example:

RACF(N): Specifies whether to provide RACF tape profile processing for this tape pool. The value N indicates that RACF tape profiles are not created, changed, or deleted for tapes in this pool, regardless of the setting of the system-wide option TPRACF.
TYPE(S): Specifies the type of pool. The value S means that it is a scratch pool.
EXPDTCHECK(O): Specifies the processing tape data sets on volumes in this pool that are expiration date protected. The value O means that DFSMSrmm takes no action but allows the operator or automated software to reply as necessary to any write-to-operator messages (IEC507D).
MEDIANAME(parmlib_default_medianame): Specifies a media name for all volumes in this pool. The MEDIANAME value for the default pool is the same value that you specify with the EDGRMMxx parmlib OPTION MEDIANAME value.
To separate storage locations by media name, any LOCDEF command media names that you define must be the same as the VLPOOL media names or a subset of the media names. See Defining storage locations: LOCDEF for information on defining storage locations.
DESCRIPTION('DEFAULT POOL'): Describes the pool.
PREFIX(*): Specifies a generic shelf location prefix that is used in operator messages, TSO subcommands, and the DFSMSrmm ISPF dialog. A single asterisk defines the default pool that contains all rack numbers or volumes not specifically included in any pool. You also have the option to define a pool name that can be used to update operator messages, displays, and can be used as a storage group.

You can also specify a SYSID operand on the VLPOOL command. SYSID associates a scratch pool with a particular system. DFSMSrmm matches the value with the SYSID operand of the OPTION command, also in EDGRMMxx. If the VLPOOL SYSID matches the OPTION SYSID, DFSMSrmm performs these functions:

A volume from this pool can be used to satisfy a scratch mount request on this system.
A volume from any other pool where its SYSID also matches the OPTION SYSID can be used to satisfy a scratch request on this system.

A volume from a pool that has no explicit VLPOOL SYSID can be used to satisfy a scratch request on a system if there are no other VLPOOL definitions that have a SYSID matching the OPTION SYSID. The SYSID values are ignored when a storage group is selected by ACS processing and when a pool is set for a non-specific volume request by EDG_EXIT100 processing. The system level pools can still be used as long as SMS ACS processing does not assign a storage group and the EDG_EXIT100 exit does not set a specific pool to be use.