Initial program
load (IPL) means load the initial (first)
programs into main storage so that the processor can use them to do
work for you. An IPL resets system storage (cleans out what was there
and replaces it with new data). In other words, IPL means start your
system. The following situations typically require an IPL:
Restart *YES / *No
- Starting local or remote operations when the system power is off
- Applying certain program temporary fixes (PTFs)
- Installing new system hardware
- Starting a system after a problem prevents all jobs from working
- Main storage dumps
AS/400 has a variety of modes, speeds, and types of initial program loads to fit a variety of needs.
Operating mode: You use the operating mode to
determine the number of options that are presented to the operator for
consideration during and after the initial program load (IPL). It can
also secure (lock) the control panel to prevent an unauthorized or inadvertent
IPL from the control panel. There are four operating modes:
- Normal (unattended)
- After the power-on, operating the system in Normal (unattended)
mode requires no operator intervention during the IPL.
When you power on the system in normal mode, it performs the IPL and
presents the Sign On screen on all available display stations. The
operator cannot change the system during the IPL. Dedicated
Service Tools (DST) and the operating system do not present any
displays during this IPL.
Use a normal mode (unattended) IPL to do this:
- Perform an IPL and run the system for most routine work
- Perform a remote IPL
- Power on and perform an IPL by date and time
- Manual (attended)
- After power-on, operating the system in Manual (attended) mode
means that an operator uses the control panel to direct the system for special
needs.
During manual mode IPL, DST and the operating system present menus and
prompts that allow you to make changes to the internal system
environment. This can include entering debug mode for service
representatives to diagnose difficult problems.
Use manual mode to IPL and run the system to perform the following actions:
- Change IPL options (including system values)
- Install the operating system
- Load program temporary fixes (PTFs)
- Make some types of system hardware upgrades
- Use DST (for advanced users and service only)
- Problem diagnosis (for advanced users and service only)
- Auto (automatic)
- Use Auto mode for an automatic remote IPL, automatic IPL by Date and Time, and an automatic IPL after a power failure.
- Secure
- Use Secure mode to prevent use of the control panel to perform an IPL. This mode is not a form of IPL; it is a means to prevent an unauthorized or inadvertent IPL from the control panel.
- IPL type A
- Use IPL type A when directed for special work, such as applying program
temporary fixes (PTFs) and diagnostic work. For example, use IPL type A
in the following circumstances:
- When IPL type B fails
- When the procedures direct you to use IPL type A
- When you suspect problems with temporary Licensed Internal Code PTFs
- IPL type B:
- Use IPL type B for routine work and when directed by a PTF procedure. This type of IPL runs the newest copy of Licensed Internal Code and is necessary when you permanently apply certain PTFs. IPL type B uses the B copy of Licensed Internal Code during and after the IPL. This copy is said to reside in System Storage Area B. This copy contains temporarily applied PTFs.
- IPL type C
- This type of IPL is reserved for hardware service representative use under the direction of Rochester development support. Attention! Do not use this function! Severe data loss can occur with improper use of this function.
- IPL type D
- Use IPL type D when directed for special work, such as installing and
reloading programs.
IPL type D loads the system programs from an alternate IPL load
source, such as a tape drive or CD-ROM.
Usually an IPL uses programs stored on the primary IPL load source (usually a disk drive). Sometimes it is necessary to perform an IPL from another source, such as programs stored on tape. To do this, you must use IPL type D to IPL from the alternate IPL load source.
Use IPL type D only during one of the following situations:
- When install or restore procedures direct you to use IPL type D
- When IPL type B and IPL type A fail (when the primary IPL load source cannot IPL the system properly) and only when directed by your support personnel
- When service directs you to perform an alternate install
IPL types: The IPL type determines which copy
of programs your system uses during the initial program load (IPL).
There are four IPL types:
Restart *YES / *No