Learning AS400 to help support the place I work for

[justsomeguyiguess]

Hi all,

I'm a software developer in Australia working for a manufacturing company running an IBM i based ERP from way back when. We have an AS400 developer but he is probably looking to retire in a couple of years, and I'd like to be able to help and understand this system better anyway. (As a computer science guy it's very nice being exposed to this very unfamiliar system)

Most business users don't see the system; we send data and commands to it to work with purchase orders/sales orders/production orders/etc, and we use an ODBC connection to pull data from it which is presented via a bespoke Access 2010 system we inherited that sources its data from SQL Server and our POWER7 machine. I'm getting more familiar with it; I can work with files, logicals, queries, accounts, save/restore libraries, can troubleshoot the RPG/400 and CL code the system is written in, etc.

I'm trying to take it to the next level and be confident maintaining the system as a whole, but this being the company's core ERP you can't really play around with it. I've got an IBM 720 off eBay, which works well because our system at work is also a POWER7 system. I've decoupled it from the HMC and just managed to do a fresh standalone IBM i install from the CDs, which is good as it matches the setup at work.


So I'm posting first to say hi, but also I'm looking for thoughts on people perhaps in similar situations: We have a 7.2 installation at work, and at home I've got 7.3 because I can't seem to downgrade the LIC it previously had on it. I've read some horror stories about people who got behind with their OS version and PTFs, and I feel like we're doing just that with our system at work; how worried would you guys be working on a 7.2 install? Is 7.2 to 7.3 a big upgrade?

Regarding my home system I've got 70 days grace period. This isn't too bad as I can reinstall without too much fuss as needed, but I'm guessing most people here don't have licensed kit at home? Are there developer editions of IBM i software or any official way to learn the system at home? What do others do here? These days when the barrier to learning most systems is made very low it seems IBM really require you to be trained within a company, or have I missed something?


Also although I like the 5250 console, and use *nix consoles often, for development and debugging I want to be able to use IBM Rational Developer i. It has some handy debugging utils, but these are mainly for ILE type binaries and we're using the pre-ILE binaries. I know there is a conversion tool that converts RPG/400 to RPG IV which can be compiled as an ILE; has anyone here got experience with this, and it is remotely feasible we could convert and recompile our ERP system in ILE binary format? It looks like as long as you convert the code and all the "/copy"d code it should be functionally identical, but with a massive codebase is an automatic conversion of the whole ERP realistic?


Finally since I'm more familiar with *nix I thought it would be good to use a Linux OS on the 720 hardware to be better able to compare to PC style computers ("IBM compatible PCs" I guess), since I still don't totally understand FSPs/LPARs/where the disk config is stored/where the LIC is installed to/what the vital product thing is about/etc. But it looks like only some ancient Red Hat Enterprise installs are supposed to work. Does anyone here use *nix (not AIX, I doubt I can get that) on a POWER7 and have any advice?


Any info/thoughts appreciated. Cheers,
KJK

[JonBoy]

Lots of questions! Welcome.

First the release level. 7.2 is going out of service - in fact I believe that you already need to pay a maintenance premium to get any support. Not my area of expertise though. For a business to rely on an out-of-date release to me is just nuts. 7.2 to 7.3 is an easy migration but going direct to 7.4 would make more sense but can Power 7 run 7.4? Again not my area.

There are publicly available free/low-cost development boxes that you can use for "play" but since you already have come at a somewhat recent release it may not be worth the effort. Off the top of my head there are pub400.de and idevcloud.com. IBM also run free loaner partitions but i cannot recall what the scheme is called - the lifetime of the partition was always too short to be of use to me.

Conversion of straight RPG/400 to RPG IV is trivial and as close to a 100% a no-brainer as you will find. Only if the package makes use of one of the unsupported features is there any issue. And since they are unsupported because they didn't really work anyway dealing with them is easy enough. Note that while RPG IV is an ILE language and sadly IBM calls it ILE RPG, it does not have to run as a full ILE language. In fact the default is to run in compatibility mode (you'll see the option DFTACTGRP(*YES) in use - that is compatibility mode). The IBM supplied conversion too converts to this. I would STRONGLY suggest converting if you are no longer taking maintenance releases for the package as you'll open the door to all sorts of wonderful built-in functions and capabilities that RPG/400 can't even dream of.

One more before I stop and let you digest this. 7.3 and 7.4 support a LOT of open source software from Python to node to php to R to .... Some is available for 7.2 but the real thrust in that area post dates 7.2. Easiest access is via ACS (Access Client Services) which offers and easy way to see what is available and to install. It is also the easy way to fire up an SSH terminal connection to PASE which is the AIX-style environment within IBM i that supports the Open Source stuff. IBM have an introductory piece here: https://www.ibm.com/support/pages/ge...ment-ibm-i-acs but there are many others on the web. For unix types coming to grips with IBM i there is a Ryver group and also a great bunch of folks on the Open Source list at midrange.com.

Hope that gives you something to be getting on with.

[Peder Udesen]

Talk to the as/400 developer and tell him you are interested in learning about the as/400, how to administer it, and how to code in it.
You could practice "peer training". First the daily tasks, then about the structure of the system, then about coding RPG etc.