Friday, February 12, 2010

Modify the login screen in Ubuntu 9.10

In Ubuntu, it's easy to customize the way your desktop looks. The menu is available at System>Preferences>Appearance. Alternatively, you could change the way your desktop looks by running this command:
$ gnome-control-center
This opens a graphical configuration tool for changing a whole bunch of settings. You can click on the Appearance button to change the desktop theme and other appearance settings.

If you want to change the way the login screen looks, you're going to have to do a little bit more work. First, you're going to have to log out. Next, you need to login through a text console. Do this by pressing:
ctrl+alt+F1
Login with your regular username and passphrase. Once you're logged in, run these two commands:
$ export DISPLAY=:0.0
$ sudo -u gdm gnome-control-center
You will see some errors, but that is alright. The command will also hang, so don't expect to see a prompt again. Instead, switch back to the graphical login screen by pressing:
ctrl+alt+F7
Instead of seeing the login screen, what you'll see is a graphical configuration tool. This tool looks the same as the one you'd see if you ran the command at the beginning of this post. Anyway, by clicking on the Appearance button, any changes you make will be reflected upon the login screen instead of the desktop. You can use this to change the wallpaper for the login screen. Another useful tweak could by to adjust the screen resolution. You can do this by clicking the Display button. Whenever you finish making your changes just click the X in the top right corner of the window. Now you should see the graphical login screen with your changes.

Keep in mind that you are still logged in to the text console. Switch back to it by pressing:
ctrl+alt+F1
And type this to logout:
$ exit
Press this to switch back to your graphical login screen again:
ctrl+alt+F7

Thursday, February 11, 2010

Setup a light weight Linux desktop with Lubuntu

Ubuntu is a great, easy to use Linux distribution. It's also (relatively) light weight when it comes to system requirements so it can be used on some older systems. That being said, if it's a really old computer, even Ubuntu may be too heavy to perform well. There is Xubuntu, which uses XFCE instead of Gnome, and is designed to be a lighter system but is still just as heavy as Ubuntu nowadays. There is a new project for Ubuntu that uses the LXDE desktop environment and is significantly lighter on the system.

Lubuntu is still in beta and so there is no official, stable release available for download. It does, however, exist in the repositories for Ubuntu 9.10 Karmic Koala. If you want to try it out, make sure your system is updated and then run this command:
$ sudo aptitude install lubuntu-desktop
This will install the full desktop package, complete with all the programs built for the LXDE environment. If you don't want to install all the extras, you can run this command:
$ sudo aptitude install --without-recommends lubuntu-desktop
When I installed the lubuntu-desktop package over an existing Karmic installation, the full package required me to download about 80MB worth of files and by leaving out some of the unneeded packages with the second method, I only had to download about 50MB of files.

Once you have Lubuntu installed, you will need to log out of your Gnome or KDE or whatever other desktop environment you are running. From the login window select your username. Now, at the bottom of the screen click on the Sessions menu and select LXDE.


 After that you can enter your pass phrase and enjoy your new Lubuntu desktop.

Tuesday, February 9, 2010

Upgrade an Ubuntu LTS release to a non LTS release

Ubuntu releases a new version of their operating system every six months. Ubuntu supports each release for 18 months with patches and updates. Every two years Ubuntu releases an LTS, or long term support, version. These LTS releases receive three years of patches and updates for the desktop version and five years of support for servers. By default, these LTS releases will only upgrade to newer LTS releases. If you have an LTS version of Ubuntu installed and want to upgrade it to a newer release version that is not an LTS release, you will have to change a setting first.

First, install the update tool:
$ sudo aptitude -y install update-manager-core
Make a backup of the config file you'll be editing:
$ sudo cp /etc/update-manager/release-upgrades /etc/update-manager/release-upgrades.orig
Now open that file:
Using gedit:
$ sudo gedit /etc/update-manager/release-upgrades

Using vi:
$ sudo vi /etc/update-manager/release-upgrades
Find the line that reads:
Prompt=LTS
Change it to say:
Prompt=normal
Update to the next release:
$ sudo do-release-upgrade