Abstract

This guide explains how to make sure your Linux system won't turn into "power saving" mode while you want it up for a long period of time (like, say, when you run an installation).

I wrote this guide partly because in 2005 I went to Piksel to produce and show the interactive installation "Travel Agent" with the Drone and S.O.U.P. collectives. Everything went (almost) fine: at the end the project was running without any critical bugs, except for one thing: we couldn't prevent it from switching off every 15 minutes!

The magic 5

Keep in mind that there are five (5) things to disable in order to get your computer to non-energy saving:

1. Disable screen saver
2. Disable DPMS in X
3. Disable screen blanking in X
4. Disable ACPI in Linux
5. Disable ACPI in the BIOS

Step 1: Disable screen saver

The first step is to disable your favorite screen saver. For instance, in KDE you can do the following:

1. Go in "Control Center -> Appearance and Themes -> Screen Saver"

2. Remove the "Start automatically" setting

Step 2: Disable DPMS in X

DPMS stands for Display Power Management Signaling. You need to disable it in X by running:

xset -dpms

Step 3: Disable screen blanking in X

Run the following command:

xset s off

To make these changes permanent, add them to your ~/.Xsession or ~/.xinitrc file.

See this article for more info.

Step 4: Disable ACPI in Linux

You need to boot your kernel with both options acpi=off and noacpi. For example if you use GRUB you can modify your /boot/grub/menu.lst file:

  title         Debian GNU/Linux, kernel x.x.x-x-x86
  root          (hd0,1)
  kernel        /boot/vmlinuz-x.x.x-x-x86 root=/dev/hda2 ro acpi=off noacpi
  initrd        /boot/initrd.img-x.x.x-x-x86
  savedefault

Step 5: Disable ACPI in the BIOS

The way to do this depends of your BIOS.

Troubleshooting

I'm not using X: I run from the terminal. Should I do something different?

If instead you're using the Linux console (not X-Windows), you'll want to use setterm instead of xset:

setterm -powersave off

Thanks

Thanks to Mathieu Bouchard and Christian Klippel who gave me all the actual tips on the #dataflow forum.