How to disable zIIP without using DCMT

Document ID : KB000045456
Last Modified Date : 14/02/2018
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Introduction:

DCMT commands to vary zIIP ON and OFF were introduced during the r19.0 Incremental Release process by APAR by RO81229.

Is there any way to vary zIIP off prior to r19.0 or if RO81229 is not applied at r19.0?

 

Instructions:

Yes.

When using zIIP, many CA-IDMS modules must be loaded from an APF authorized load library. Even without the new DCMT commands to vary zIIP ON and OFF, it is at least possible to force zIIP OFF by having one of these modules loaded from a library which is not APF authorized.

For example, RHDCUXIT is one such module. This can be achieved by the following:

1.    Copy your RHDCUXIT module to a library which is higher in the CDMSLIB search chain and is not APF authorized.

2.    Execute the command DCMT VARY NUCLEUS MODULE RHDCUXIT NEW COPY

3.    Execute the command DCMT VARY NUCLEUS RELOAD

This will refresh RHDCUXIT, and due to the fact that it is now loaded from a non APF authorized load library, it will also vary zIIP off.

Messages similar to the following will appear in the dc-log:-

05:21 IDMS DC283001 V65 USER:XXXXXX NUCLEUS MODULE RHDCUXIT MARKED TO NEW COPY
05:21 IDMS DC283916 V65 USER: XXXXXX ZIIP=N FORCED. NUCLEUS MODULE RHDCUXIT LOADED FROM AN UNAUTHORIZED LIBRARY
05:21 IDMS DC283003 V65 USER: XXXXXX NUCLEUS MODULE RHDCUXIT RELOADED
05:21 IDMS DC283004 V65 USER: XXXXXX CSA/NUCLEUS VECTOR TABLE UPDATED FOR NUCLEUS MODULE RHDCUXIT

Note that if this is done, there is no way to re-enable zIIP without cycling the CV (and ensuring that RHDCUXIT will be loaded from an APF authorized load library in the new cycle).

 

Additional Information:

For more information on the DCMT commands referenced above, see the manual CA IDMS System Tasks and Operator Commands chapter 5 “DCMT VARY Commands”.

For a list of the CA-IDMS modules which must be loaded from an APF authorized library when using zIIP, see TEC1524878.