Preventing installation problems

• Use z/OS macro libraries for your IMS stage 2 definition. IMS runs only under z/OS .
• Include the libraries from which IMS is loaded and executed in the appropriate authorization table, so that the control region executes as an APF-authorized program. In z/OS, IMS runs as an authorized program.

  Related reading: For information about APF authorization, see IEAAPFxx (authorized program facility list) in z/OS MVS Initialization and Tuning Reference.

• Use JOBLIB or STEPLIB DD statements instead of having the IMS.SDFSRESL in LNKLSTxx (those data sets concatenated to SYS1.LINKLIB). If IMS.SDFSRESL is in LNKLSTxx, it is possible for a different IMS release level (whose own IMS.SDFSRESL is not properly APF authorized) to load the modules from LNKLSTxx. The incompatible module release level can cause unpredictable results.
• Update the program properties table. The IMS control region operates as a job step task or as a system task. All control region execution is in supervisor state. See Updating the IBM-supplied z/OS Program Properties Table for more information.

Related reading: For additional information on maintaining system integrity when running under z/OS, refer to z/OS MVS Programming: Authorized Assembler Services Reference.