Thursday, February 18, 2010

Fixing the monitor's low resolution after Ubuntu 9.10 installation

During a fresh installation of Ubuntu 9.10 (karmic) on a Dell Dimension 3000 standard system, the monitor resolution could no longer support any mode higher than 800x640. An initial twinge of frustration was coupled with confidence that the problem was tractable. This is the short story of how the Ubuntu and open source communities helped the solution.

Historically, whenever I encounter display problems I look at the xorg.conf file which is usually found in /etc/X11. On this installation day I was surprised to discover that xorg.conf was not in its usual place. Indeed, my surprise became something unameable when a search of the entire filesystem revealed that the file did not exist. While it is possible that a step or two after installation could have removed the file, the fact remains that some high-level procedure leaves me without an xorg.conf.

It was tempting to search out what mechanisms have replaced xorg.conf and to understand the advertised improvements of the new way, but in the short term I just wanted better resolution. Somewhere within the first few tens of minutes I found what turned out to be a solution, but I initially hoped for a simpler way. I learned a valuable lesson in this dismissal — read and understand before trading away over an hour searching for a presumed simpler way.

Searching the Ubuntu wiki revealed the article titled Reverting the Jaunty Xorg intel driver to 2.4 and my initial reaction was that my system (karmic) was newer than the one in the article (jaunty). Even so I saw the seven steps, four explicit and three others potential, and thought this might work. However, two of the possible steps (obtaining a validation key) were something I remembered doing before with some trouble. The other possible step, related to the key, was opening a port on my firewall. This final step is the one that sent me looking elsewhere, not because I didn't want to make the change but because I sought something that smacked less of system administration to the normal home user. In the end, neither of the potential steps were necessary.

The four steps to solving the resolution took less than 4 minutes to accomplish.

  1. Add the following two lines to the bottom of /etc/apt/sources.list (I used sudo vi /etc/apt/sources.list to do the edits; use your favorite editor as an administrator)
    deb http://ppa.launchpad.net/siretart/ppa/ubuntu jaunty main
    deb-src http://ppa.launchpad.net/siretart/ppa/ubuntu jaunty main
    
    • NOTE: I did indeed use 'jaunty' rather than 'karmic'.
  2. Update package list
    sudo apt-get update
    
  3. Install the xserver-xorg-video-intel-2.4 package
    sudo apt-get install xserver-xorg-video-intel-2.4
    
    • NOTE: A warning appeared that "packages cannot be authenticated!", but I was able to install "without verification." This is related to my inability to add the validation key and is not my preferred mode of operation. Even so, the key was not a necessary step in the present solution.
  4. Restart the display
    sudo /etc/init.d/gdm restart
    

The display immediately went to a much more reasonable resolution. Problem solved.

2 comments:

  1. Can you now configure the login screen?
    This may also work when installing Ubuntu in a virural box.

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  2. No gdm configuration successful yet. A few attempts using /etc/gdm/custom.conf and /etc/gdm/gdm.conf-custom did not seem to change anything. Through gdmsetup I was able to change the login to be automatic for me, but that was the only change I could make.

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