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  • 1.  IBM i version downgrade

    Posted Mon February 20, 2023 02:39 PM


    I need help with a task that I have not done before. I have a S1014 server with IBM i 7.4 Operating System. For legacy applications I need operating system 7.3. Where can I find the step by step for this operation? and the considerations. Any indication is appreciated.




  • 2.  RE: IBM i version downgrade

    IBM Champion
    Posted Tue February 21, 2023 02:22 AM
    Edited by Satid Singkorapoom Tue February 21, 2023 07:23 AM

    Dear Diego

    There has NEVER been a support for downgrading IBM i release since day one of OS/400.  The only thing you can do in this case is that you do what is called a "scratch" install of IBM i 7.3 just like you do for a machine that comes with no IBM i installed at all.     

    One more consideration is that if you already have users data objects in this IBM i 7.4 machine that you saved to tape, there has never been a support for restoring these objects to any previous IBM i release(s).  You need to use other non-save-and-restore methods which can be quite time consuming. 

    But based on my past experience, I figure there may be a silver lining in this dark cloud for you.

    In general, an IBM i-based application that can run in IBM i 7.3 should also run in IBM 7.4 unless there is any known specific restriction or explicit error that the owner of the app is aware of, but this is usually known only when a test run is done. In the past 34 years of IBM i, there were very few keystone releases that required a lot of effort to modify the applications so they can run. For example, for some customers (not too many in my experience), upgrading from pre-7.2 to 7.2 or later releases can require a handsome effort to handle some Queries (QRYDFN, OPNQRYF, etc.) that fail because of a move from CQE to SQE for Query (QU1) product.  I do not see there is any such major change in release 7.4 compared to 7.3 that would cause this difficult prospect. 

    So, I suggest that you try a test run of your app in IBM i 7.4.  Is your application developed in-house or an ISV product?  For the former, there is very good chance you should be able to run it in IBM i 7.4. For the latter, there still is a good chance you also can.  In my long experience with IBM i, the reason an ISV would say this and that release of its application is not supported in this and that IBM i release yet is because they have not done the test run of the app in that IBM i release yet.  But I used to help many customers perform test run of their ISV app in a new "not-yet-supported" IBM i release without any, or with minimum, problem. The crucial success factor is to make sure the test run touches on all current functions that the customer is using. And whenever any error is encountered, pay attention to understand the error message(s) or find an expert who can help interpret the error(s) and then provide suggestion for rectification. 

    If you can tell me some information about your app (product name and version or for in-house one, what language and version is used), I may be able to provide more response. 

    Let me know if you have any further questions. Please post any future questions having to do with IBM i in the community group named IBM i Global.

    Wishing you best of luck.

    Education is not the learning of facts but the training of the mind to think. -- Albert Einstein.
    Satid S.