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

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.

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

Install Firefox 3.6 in Ubuntu 9.10

Mozilla released Firefox 3.6 this morning. Going by past behavior, this release will likely not find its way into the official Ubuntu repositories before Ubuntu 10.04 is released this coming April. If you want to be able to benefit from the latest features in Firefox 3.6 now, you can install it very easily using Ubuntuzilla.

I've written about Ubuntuzilla before. It is a Python script that will download and install the latest version of three Mozilla products: Firefox, Thunderbird and Seamonkey. You can run this command to download the latest version of the Ubuntuzilla installer:

$ wget http://downloads.sourceforge.net/project/ubuntuzilla/apt/pool/main/u/ubuntuzilla/ubuntuzilla_4.8.3-0ubuntu1_i386.deb

Now to install it:

$ sudo dpkg -i ubuntuzilla_*.deb

Run this command to install the latest version of Firefox:

$ ubuntuzilla.py

 You will have to run through a series of questions that are really straightforward and when you're done you will have the latest version of Firefox installed.

Beat the 4GB RAM barrier in 32-bit Linux

In all operating systems, there is a limit to the total amount of system memory that can be addressed. In 32-bit systems, this limit is at 4GB. This is one of the reasons for the current push toward 64-bit operating systems. A 64-bit operating system can support a theoretical 16.3 petabytes of system memory. This maximum amount of system memory includes not only the RAM but also any dedicated video memory on discrete graphics cards. For this reason, many users with 4GB of RAM installed and a video card will see somewhere between 3 and 3.5GB of systems memory instead of their full 4GB that is installed.

In Ubuntu Linux, there are a few ways around this problem. The obvious solution is to switch to the 64-bit version of the operating system. The downside to this approach is that it requires reinstalling the operating system and there may be software compatibility issues. The other way is to install a kernel that supports PAE. In short, PAE is a way to get a 32-bit kernel to support more than 4GB of system memory. In Linux, a PAE enabled kernel is able to use up to 64GB of total system memory.

If your system has 4GB or more of RAM installed and the system isn't reading as all of it being there, you can run this command to install the PAE enabled kernel:

$ sudo aptitude install linux-generic-pae

You will, of course, have to restart in order to use this new kernel. After restarting you can verifying that you are, indeed, using the kernel by running this command:

$ uname -r

You should see a number followed by the string "generic-pae". As of this writing, the most current version is 2.6.31-17-generic-pae. You can also check how much RAM the system can see by using this command:

$ free -m

 This will show you system memory usage, measured in megabytes. The top left number represents the total RAM the system is able to use.

A word of warning, you won't need to install the PAE enabled kernel if you are running Ubuntu server. The server releases are running a server version of the kernel that is optimized differently and already supports PAE.

Install full or minimal GUI in Ubuntu server

The server installation of Ubuntu does not include a graphical user interface, or GUI. If you find that you want the GUI after all, you can easily install it without reinstalling the operating system with the desktop version.

To install the full GUI desktop environment, complete with all the bundled applications found on the desktop version of Ubuntu, run this command:

$ sudo aptitude -y install ubuntu-desktop

 If, on the other hand, you don't want all of the bundled applications found on the desktop version of Ubuntu and only want the GUI, run this command:

$ sudo aptitude -y install gdm

To start the GUI, you'll need to run this command once you have logged in from the terminal:

$ startx

If you want the GUI to start automatically upon booting, follow the instructions from this post.

Enable Custom Sounds on the Motorola Droid

Although it is not immediately apparent, the Motorola Droid does support custom ringtones and other sounds. All you have to do is create the appropriate directory structure on the microSD card. First, connect the Droid to your computer. Then, navigate to the memory card and create a folder called "Media". Inside the "Media" folder, create a folder called "Audio". Inside the "Audio" folder, create three folders. Their names should be "Alarms", "Notifications", and "Ringtones". Now just drag-n-drop the sound files you want into their respective folders. When you disconnect the phone from your computer the new sound files will show up on the appropriate menus.