Using Power Management

The power.conf File

The power.conf file in the /etc directory lets you set the configuration for managing system power. It also enables you to set display power configurations that are followed for that display when a CDE or OpenWindows desktop isn't present. (See Chapter 2, Managing Monitor Power for details on managing display power in those windowing environments.)

The default /etc/power.conf file has the following content:

# Power Management Configuration File
# Putting an entry in this file will only be effective if the 
# driver for the device supports device power management. 
# After the file is modified, pmconfig(1M) command must be
# executed to activate the new change.
# Fields must be separated by white space or semicolons.
# Note that physical dependents are automatically considered
# by the power management framework.

# Name           Threshold(s)       Logical Dependent(s)
/dev/kbd         1800
/dev/mouse       1800

# NOTE: The entries below are only used when no window
# system is running. When running the window system, monitor
# power management is done by the screen saver functions.

/dev/fb          0 0               /dev/kbd     /dev/mouse

# Auto-Shutdown  Idle(min)  Start/finish(hh:mm)  Behavior
autoshutdown     30          9:00 9:00           default

statefile        /.CPR

Logical Dependents

In the /etc/power.conf file, there are entries for Logical Dependent(s). Each is a physical device (such as a mouse) that has activity that is related to another device (such as a frame buffer) but is not physically attached to it.

If a logical dependent device is active, then the main device is considered active as well. This affects idle times for the main device.