This post is just a cut and paste job from the Ubuntu SwapFaq for my future reference Ubuntu installation.
The swappiness parameter controls the tendency of the kernel to move processes out of physical memory and onto the swap disk. Because disks are much slower than RAM, this can lead to slower response times for system and applications if processes are too aggressively moved out of memory.
The default setting in Ubuntu is swappiness=60. Reducing the default value of swappiness will probably improve overall performance for a typical Ubuntu desktop installation. A value of swappiness=10 is recommended, but feel free to experiment. Note: Ubuntu server installations have different performance requirements to desktop systems, and the default value of 60 is likely more suitable.
To check the swappiness value
# cat /proc/sys/vm/swappiness
To change the swappiness value A temporary change (lost on reboot) with a swappiness value of 10 can be made with
# sudo sysctl vm.swappiness=10
To make a change permanent, edit the configuration file with your favorite editor:
# gksudo gedit /etc/sysctl.conf
Search for vm.swappiness and change its value as desired. If vm.swappiness does not exist, add it to the end of the file like so:
vm.swappiness=10
Save the file and reboot.
Tags: swappiness, sysctl, Ubuntu
Posted by Hans-Henry Jakobsen
This is a short HOWTO on disabling IP version 6 support on your ethernet devices like eth0 on Ubuntu 11.10.
I guess you can do this on earlier version of Ubuntu as well.
net.ipv6.conf.all.disable_ipv6 = 1
Run the following command to make this change effective immediately
# sudo sysctl -p
A result from this command could be like this
net.ipv6.conf.all.disable_ipv6 = 1
To check that IPv6 has been disabled or not, run the following command from your console window
# ip a | grep inet
IPv6 has been disabled if this command does not return any IPv6 addresses.
Tags: 11.10, howto, ipv6, sysct, sysctl.conf, Ubuntu, ubuntu oneiric
Posted by Hans-Henry Jakobsen
This post is a short howto to fix/workaround the problem with low volume in some Ubuntu 11.04 installations.
The fix for me was to open a console window (as the user I’m logged in with) and start the alsamixer
# alsamixer
You will then see the alsamixer window. Use the left/right arrow keys and choose the device you would like to configure. In my case it was the headphone.

Choose which sound card you would like to configure on the headphone by pressing the F6-key. Make your choice and press the Enter-key.

Use your up/down arrow keys to choose the right volume for your configuration. You should have some audio playing while you configure to determine the right value.

Press the Esc key to exit alsamixer when you have found the right volume. Your settings are persistent and will survive a reboot.

You are now done with configuring your sound card.
Tags: 11.04, alsamixer, howto, Ubuntu
Posted by Hans-Henry Jakobsen
This post describes how you can change from the Unity Desktop environment that is the default desktop environment to the Gnome Desktop in Ubuntu 11.04 (Natty Narwhal) Beta.
The desktop environment I like to use is the desktop named Ubuntu Classic and you can change to this desktop by going to (or searching for) System Settings -> System-> Admin -> Login.

Here you can choose between
Log out of the Unity desktop after choosing Ubuntu Classic and pressing the Close button.
You can now choose your desired desktop environment from the bottom of the screen. If you would like to use the Gnome Desktop environment like the one we are used to in Ubuntu 10.10 and earlier, just choose Ubuntu Classic and login again.
Tags: 11.04, gnome, natty narwhal, Ubuntu, unity
Posted by Hans-Henry Jakobsen
A short description on how to change the console language in Ubuntu 10.04 LTS Server but it should work on other Debian flavours as well.
# dpkg-reconfigure console-data
Posted by Hans-Henry Jakobsen