Filtering with LOADxx

The LOADxx filter keywords HWNAME, LPARNAME, and VMUSERID allow you to use a single LOADxx member to define IPL parameters for multiple systems. At IPL, the initial values of the keywords are set to match the actual values of the system being IPLed. The filter keywords are used to optionally change the IPL parameters.

Note: If a filter keyword is not applicable to a particular system, it is initialized to blanks at IPL. Subsequent specification of this filter keyword within LOADxx resets it.

The keywords control filtering in a hierarchy with HWNAME on the top and VMUSERID on the bottom. Figure 1 shows this hierarchical relationship. The HWNAME parameter is used to specify the Control Processing Complex (CPC) name. HWNAME also sets LPARNAME and VMUSERID to their default values. The LPARNAME parameter, the next level in the hierarchy, is used to set the Logical Partition name. LPARNAME also sets VMUSERID to the default value. The value of HWNAME is unchanged. The lowest level of the hierarchy, the VMUSERID parameter, specifies the user ID of a z/VM® system under which a z/OS® image is running as a guest. Due to the hierarchical relationship of these keywords, the following rules apply to the specifications in your LOADxx member:

  1. Keyword HWNAME is in effect from its occurrence to the next HWNAME statement in the member or to the end of the LOADxx member.
  2. Keyword LPARNAME is in effect from its occurrence to the next HWNAME or LPARNAME statement or to the end of the LOADxx member.
  3. Keyword VMUSERID is in effect from its occurrence to the next HWNAME, LPARNAME, or VMUSERID statement or to the end of the LOADxx member.

There is no way to explicitly indicate that you want the LPARNAME parameter or the VMUSERID parameter reset to their default values. If the system that is being IPLed is not running as LPAR mode or on VM, LPARNAME and VMUSERID might not be meaningful. This is a case when you might want to reset these values. As previously discussed, specifying the HWNAME parameter resets the LPARNAME and VMUSERID parameters to their default values. You can also reset just the VMUSERID parameter to its default value by specifying the LPARNAME parameter.

See Filtering example for examples of how to set the keywords.
Figure 1. LOADxx filtering hierarchy
Example of LOADxx Filtering Hierarchy

When another LOADxx statement (such as SYSCAT or IODF) is specified, the current HWNAME, LPARNAME, and VMUSERID filters are compared to the actual system values. If they all match, that LOADxx statement is accepted as applicable to the system that is being IPLed. See Statements/parameters for LOADxx for specifics about each keyword.

Parent topic: LOADxx (system configuration data sets)