Controlled shutdown concepts

Before you use a power-handling program to control system shutdown, you may want to familiarize yourself with related concepts.

Battery backup unit
A battery backup unit provides a safety net for users who do not have an uninterruptible power supply or those with a failed uninterruptible power supply.
Handling uninterruptible power supply conditions when no power-handling program exists
You might need to change some system values when you do not have a power-handling program. These are considerations when you do not have a power-handling program to handle controlled system shutdown.
IPL considerations for uninterruptible power supply
When the system performs an initial program load (IPL), the Licensed Internal Code verifies various internal switches to see if the system was correctly turned off.
Power-loss controlled shutdown
The power-loss controlled shutdown mechanism enables the system to shut down in an orderly fashion following a loss of utility power. The power-loss controlled shutdown mechanism is available only if you connected the system to an uninterruptible power supply.
Power restore IPL system value (QPWRRSTIPL)
This value controls what happens if the system ends when utility power is interrupted and then restored at a later time.
Uninterruptible power supply
An uninterruptible power supply provides a source of ac power if utility power should fail. Typically, an uninterruptible power supply has a finite backup time.
Uninterruptible power supply delay time system value (QUPSDLYTIM)
The uninterruptible power supply delay timer (QUPSDLYTIM) controls the length of time that the system waits before saving main storage and powering down the system.
Uninterruptible power supply message queue system value (QUPSMSGQ)
The uninterruptible power supply message queue (QUPSMSGQ) system value determines which message queues the power supply messages are sent to.
Uninterruptible power supply messages
Several error messages are related to uninterruptible power supply.
Weak battery condition signal from uninterruptible power supply
When the battery on the system falls below a specific level of charge, the uninterruptible power supply issues a weak battery condition signal.

Parent topic: Controlling system shutdown using a power-handling program