A minimal xorg.conf (Shallow Thoughts)

Akkana's Musings on Open Source, Science, and Nature.

Thu, 10 Apr 2008

A minimal xorg.conf

Dave has been experimenting with xorg configuration lately -- trying to figure out why the latest Xorg no longer supports 1600x1200 on his monitor. (I've looked for bug reports and found gazillions of them, all blaming it on the video card but involving three different makes of video card, so color me skeptical.)

Anyway, part of this has involved taking out parts of his /etc/X11/xorg.conf file to see which parts might be causing the problem, and he's found something interesting.

What do you suppose is the minimal useful xorg.conf file? You might suppose, oh, screen and monitor sections, an input section for the keyboard and another one for a generic mouse, and that might be all you need ... right?

Okay, try it. Let's start with a really minimal file -- nothing -- and gradually add sections. To try it, make a backup of your current xorg.conf, then zero out the file:

cd /etc/X11
mv xorg.conf xorg.conf.sav
cp /dev/null xorg.conf

Now exit X if you hadn't already, and start it up again (or let gdm do it for you). Be prepared to do repairs from the console in case X doesn't start up: e.g. sudo cp /etc/X11/xorg.conf.bak /etc/X11/xorg.conf

What happened?

In my case, on the laptop running Hardy beta, X starts right up and looks just the same as it did before.

xorg.conf -- who needs it?

A specious question, of course, which has a perfectly good answer: anyone who needs a resolution other than whatever xorg picks as the default; anyone with additional hardware, like a wacom tablet; anyone who wants customizations like XkbOptions = ctrl:nocaps. There are lots of reasons to have an xorg.conf. But it's fun to know that at least on some machines, it's possible to run without one.

Update: turns out this is part of Ubuntu's new BulletProof X feature. It doesn't work on other distros or older versions. Thanks to James D for the tip.

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[ 10:25 Apr 10, 2008    More linux | permalink to this entry ]