i5/OS concepts

Learn about the essential components of the iSeries™ server, including the basics of work management, how to interact with the operating system, and system maintenance.

IBM i5/OS™ is the operating system for the iSeries servers. It manages hardware and software resources, and provides an interface that allows you to work with the iSeries server. To best use the operating system, you need to be familiar with the following system concepts.

• Messages
  Messages are communications sent from another user, from the operating system, or from an application. Learn about the different kinds of messages and how to interpret and respond to them.
• i5/OS commands
  i5/OS uses control language (CL) commands to interpret instructions from users. Learn the basic rules for using CL, and how to get detailed help for any CL command.
• Security and user authority
  The operating system determines which resources users might access based on information in their user profiles and the security strategy implemented for this system. Learn about security settings and how to manage user authorities efficiently.
• Files and file systems
  Files and file systems present information about database file management, spooled files, tape files, and the integrated file system capabilities of the IBM iSeries server.
• i5/OS restricted state
  At times, it is necessary to place the operating system in restricted state. This is a concept unique to the i5/OS operating system and must only be performed when necessary. Learn about restricted state and when it needs to be performed.
• Jobs
  All work done by the iSeries server is divided into units called jobs. Learn about the types of jobs, and how to find, monitor, and work with them on the iSeries server.
• Subsystems, job queues, and memory pools
  You can control work on the servers by working with the resources used to process jobs.
• Objects
  Everything on the system that can be worked with is considered an object. Objects provide a common interface for working with system components. This topic discusses the different kinds of objects and how to work with them.
• Logs and journals
  Record keeping is an important way for the system to protect data and track system problems. This topic describes what logs and journals are for and how to use them.
• Software fixes
  Use fixes to install and manage software and software updates.