Step 2. Determine where to specify system parameters

The IEASYSxx parmlib member specifies the system parameters that the system is to use. The operator can specify system parameters during initialization, or accept the system parameters specified in IEASYSxx. IEASYS00 is the default member; you can specify additional IEASYSxx members as needed.

You can specify the suffixes of IEASYSxx members that the system is to use in any of the following places:

The LOADxx parmlib member
The IEASYMxx parmlib member
The SYSP parameter, specified in response to the SPECIFY SYSTEM PARAMETERS prompt.

When different systems in a multisystem environment require different IEASYSxx members, consider specifying the IEASYSxx suffixes in IEASYMxx. You can specify the IEASYSxx suffixes for all systems in one IEASYMxx member.

The specific advantages to using IEASYMxx over LOADxx are as follows:

IEASYMxx can specify unique IEASYSxx members for as many systems as you need.
When you use IEASYMxx, LOADxx can point to IEASYMxx; therefore, you do not have to code unique LOADxx and IEASYSxx members for each system.

For example, the SYSPARM statements in the IEASYMxx member in Figure 1 specify the IEASYSxx members to be used for three different systems:

Figure 1. Example IEASYMxx parmlib member

  SYSDEF  HWNAME(MVS3090) LPARNAME(SYSCA)
          SYSPARM(01,L)

  SYSDEF  HWNAME(MVS3090) VMUSERID(VMSYSCB)
          SYSPARM(03,L)

  SYSDEF  HWNAME(SYSCC)
          SYSPARM(01,02,L)

See Step 4. Create an IEASYMxx parmlib member for more information about how to specify system parameters in IEASYMxx.

Depending on where you specify the suffixes of IEASYSxx members that the system is to use, the system overrides or concatenates the members:

If you specify the suffixes in IEASYMxx or LOADxx, the system will concatenate the members according to the scheme shown in Table 1.
If you specify the suffixes in IEASYMxx or LOADxx and the operator specifies the suffixes at IPL, the suffixes that are specified by the operator overrides suffixes in IEASYMxx or LOADxx.

The system always processes the IEASYS00 member first, regardless of where you specify IEASYSxx suffixes. If the same parameter appears in both IEASYS00 and a specified alternate IEASYSxx list, the value in the alternate list will override the value in IEASYS00. Also, a parameter value in a later specified IEASYSxx list overrides the same parameter in an earlier specified list. See the description of the IEASYSxx member for more information.

For example, suppose you create the following IEASYSxx members and specify their suffixes in the indicated places:

LOADxx - 01,02
IEASYMxx - 03,04
Console SYSP (WTOR) - 05,06

Table 1 shows how the system concatenates or overrides the suffixes:

Table 1. Precedence of system parameter specifications
LOADxx	IEASYMxx	Console SYSP (WTOR) (See note)	Resultant IEASYSxx noncatenation
None	None	None	00 (default)
(01,02)	None	None	(00,01,02)
(01,02)	None	Null response	(00)
(01,02)	(03,04)	None	(00,01,02,03,04)
(01,02)	(03,04)	(05,06)	(00,05,06)
None	(03,04)	None	(00,03,04)
None	(03,04)	(05,06)	(00,05,06)
None	None	(05,06)	(00,05,06)
Note: “None” means that no IEA101A prompt was issued. This is the case when the IMSI prevents the system from prompting the operator for system parameters. This is different from the case where the IEA101A prompt is issued, but the user response to the message is null. A null response is equivalent to a response of SYSP=00.

If any of the IEASYSxx suffixes specified in LOADxx, IEASYMxx, or in response to a WTOR are not valid, the system issues message IEA336A to request that you specify system parameters again.

The number of IEASYSxx members that you use for a multisystem environment depends on the desired result from your system parameter concatenation and your preferences about how the information is organized. See Table 2 for more information.

Table 2. Recommended actions for IEASYSxx members
Desired result	Situation	Recommended action
One IEASYSxx member	Different systems require unique system parameters	Code one IEASYSxx member; specify system symbols to represent unique system parameters.
One IEASYSxx member	Different systems use the same system parameters	Code one IEASYSxx member to be shared by all systems.
Multiple IEASYSxx members	Different systems require unique system parameters	Code separate IEASYSxx members, for each system, where appropriate; specify the IEASYSxx members in a shared IEASYMxx member.