IBM i Operating System in more detail

Introduction to the IBM i system menu

Everything is an Object In IBM i (AS/400), all system resources—programs, files, commands, and even libraries—are encapsulated as objects. This abstraction provides a unified way to manage diverse elements without needing separate handling rules

What are the typical nouns used in IBM i commands, and what do they represent?

IBM i Libraries and Objects

Library List, Types and Objects in more detail

The IBM i System uses library lists to determine where a job can find the objects it needs. Each job on the system has a library list attached to it.

The Integrated File System (IFS) is a file system used in IBM i Power Systems (also used on the older AS/400 and iSeries machines). It operates as a storage system that replicates the classic folder/document folder used by Unix and windows systems. It allows full operability with these other systems.

QDLS (Document Library Services) is an old, legacy file system within IBM i. IBM states that QDLS dates back to System/36 and System/38 and is maintained only for backward compatibility. [ibm.com]

We all know that a database stores data - but what is the difference between a Table, a Physical File, a Logical File, a View, an Index?

DDS Definitions for Physical File - How to Create a file with Default Values

Let's go through a code example of creating a *PF - Physical File

Logical Files are IBM's way of saying "lets look a this file data in a certain sequence". They really are quite logical. Let's go through a code example of creating a *LF - Logical File

It's time to grab some old AS400 Physical Files and drag them kicking and screaming into the IBM i SQL Age...

Demystify SQL Stored Procedures on IBM i and make them feel less like arcane magic and more like practical wizardry.

Journaling is a function which records the changes in a file in a journal. These record images are used to recover the changes in the file should the system ends abnormally. Commitment control is a function that allows you to define and process a no of changes to database files as a single unit (transaction).

The IBM i System utilises various types of libraries to organise and manage objects within the system. Library lists, which are associated with each job, specify the libraries that the job can access.

To configure your IBM i system to enforce long passwords with a minimum of 10 characters and require at least one special character, you'll need to adjust several system values related to password rules. Here's a breakdown of what to set:

If you are new to IBM i or just need a refresher, today is all about Licensed Programs. These are the building blocks that extend your system's capabilities beyond the base OS. We will keep it straightforward, technical, and hands-on. Think of this as your quick-start lesson to understanding what they are, why they matter, and the basics of installing and uninstalling them.

What is an IBM PTF? That is the question I get asked all the time by new IBM i programmers and even some old hands who have never really dug into the details. So let me give you the clear, straight answer right up front: An IBM PTF, or Program Temporary Fix, is IBMs official way of delivering targeted updates to your IBM i operating system and its licensed programs. Think of a PTF as a smart software patch. It fixes bugs, plugs security holes, improves performance, adds new features, and in many cases bundles up as a Technology Refresh that keeps your system modern without forcing a full OS upgrade. These are not random one-offs. PTFs come in different shapes: individual fixes for a specific problem, group PTFs focused on one area like security or Java, cumulative packages that roll up hundreds of fixes, and those powerful Technology Refresh groups that stack nicely on top of each other.

It's time to dive into the world of Independent ASPs (iASPs) on IBM i. We begin with the basics of ASP types—comparing System ASP, Basic User ASPs, and Independent ASPs to familiar Windows drive concepts—then dive deep into what makes iASPs unique: detachable storage pools with separate databases, private vs. switchable configurations, and vary on/off capabilities. A detailed architecture diagram illustrates SYSBASE alongside multiple iASPs, each with isolated libraries, IFS directories, and relational databases, highlighting namespace isolation where identical library names can coexist across different iASPs (as long as only one ASP group is active per thread). Practical command examples like SETASPGRP, VRYCFG, and job-description overrides demonstrate real-world access methods, while the final chapter covers essential best practices including user profile settings, backup strategies (why Option 21 skips iASPs!), SMAPP considerations, and application design tips for maximum reliability and performance.

In this video, we explore the PRTCMDUSG command on IBM i, a powerful tool for analyzing command usage and understanding how commands are structured and accessed. Whether you're an RPG developer, system admin, or just diving into IBM i command architecture, this tutorial will help you: ✅ Understand what PRTCMDUSG does 🛠️ Learn how to run it and interpret its output 📁 See real-world examples of command usage reports 🔍 Discover how it can help with debugging and documentation

WRKACTJOB is one of the most useful commands on IBM i, but once you move past the basics, it opens up a whole world of detail that many programmers never fully explore. Hidden behind those columns and options are powerful insights into performance, job behavior, wait conditions, and system health. In this lesson, we’ll go beyond the surface and unpack WRKACTJOB in a way that makes every field, filter, and function feel intuitive. By the end, you’ll read this display like a seasoned operator spotting issues faster, understanding system flow more clearly, and making smarter decisions with confidence.