AS400 Tutorials

5 Minute AS400 Tutorial

May 27th, 2009 by John

Three Essential AS/400 Tasks You Need To Know

The operating system that runs on an AS/400, iSeries, i5 is known as OS/400 or i5/OS and it is command and menu driven. At its heart everything tends to be a command and even the menus that you see use commands behind the scenes. All of these commands are known as control language.

AS400 commands tend to be three letter abbreviations of two or more words put together. For example the word “work” is commonly used in several commands and is abbreviated as wrk. Printable output on an AS/400 is known as spool files and commands to work with those are abreviated as splf— ok so thats four letters but it is a rare exception.

So if we put together Work and Spool Files we ge the command “wrksplf” Work with Spool Files and it allows you to maintain your printable output that is still residing on the system. And by the way commands are entered on the command line at the bottom of menus and denoted with the “===>” symbol.

To see a list of AS400 commands that have been catagorized into groups type in “go verb” on the command line. As you will see there are *alot* of commands. Ultimately you will probably only ever use 20% of them, and realistically even for day to day system administration less than that.

You can also prompt any command by typing it in and pressing the F4 key on the keyboard. This prompting will display more detail about the command and provide all of the available parameters that go along with it.

Everything that runs on the AS400 is called a job. And all of the jobs run within their own areas known as subsystems. To see a list of all the jobs currently running on the system you will use the command wrkactjob which stands for Work with Active Jobs.

Without getting into a bunch of techno jargon, subsystems are a way to run jobs that jobs can be allocated system resources like memory and CPU processing time. For example printers run in there very own subsystem called QSPL, which tends to have its own pool of memory allocated to it. That way others jobs in the system don’t use that allocated memory and vice versa. The memory can be reallocated easily if need be but that will be covered in another topic.

Out of the box an AS400 will have adequate subsystems configured to get you up and going… as time goes on your can create more subsystems or change the pre-configured ones if need be.

Lastly let’s take a look at how to shutdown or restart an AS400. Starting up an AS400 or restarting is know as an Initial Program Load or IPL for short. This is a rather straight forward process but can take quite a bit of time to complete.

In a very brief nutshell upon startup the system checks everything out and loads up the operating system and related systems to make the system opertational. During an IPL is most often when you will experience a hardware failure… not to worry though because most hardware failures that occur on an AS400 can be replaced while the machine is running. This includes hard disks, redundant power supplies and even memory.

So to shutdown or IPL a system you will use the Power menu which you access by typing in “go power” on the command line or alternatively using the Power Down System or pwrdwnsys command. Most people opt for using pwrdwnsys.

-John Andersen

P.S. To get all my closely guarded AS/400 and IBM i administration tips and techniques click here. You’ll cut your learning time to be up and running, even if your totally new to the system, by tonight.

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