Reinstall Grub 2 after installing Windows 7 or reinstalling Windows Bootmanager (MBR)

An easy way is to use a Ubuntu livecd.

• Boot Ubuntu 11.10 with the livecd
• Start the disk utility with the command palimpsest to find the partition where Ubuntu was installed to. On my hard disk it was /dev/sda5.

• Use your partition number instead of the 5…:

sudo -i
mount /dev/sda5 /mnt
grub-install --root-directory=/mnt/ /dev/sda

• restart

Install Gnome on Ubuntu 11.10 server

To install Gnome on your Ubuntu 11.10 server you should have defined the following repositories in /etc/apt/sources.list:

deb http://de.archive.ubuntu.com/ubuntu oneiric main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu oneiric main restricted universe multiverse

deb http://de.archive.ubuntu.com/ubuntu oneiric-updates main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu oneiric-updates main restricted universe multiverse

deb http://de.archive.ubuntu.com/ubuntu oneiric-security main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu oneiric-security main restricted universe multiverse

If you have them in your sources file, install gnome shell with the command:

sudo apt-get update
sudo apt-get install gnome-shell
sudo apt-get install gdm

To start the Gnome shell use:

sudo gdm

Gnome-shell Shutdown/Restart Button

• Click on the user account at top-right corner.
• Press down Alt key. You’ll see the “Power Off…” option.

How To Upgrade To Ubuntu 11.04 Natty Narwhal via Linux Terminal

To upgrade to the Ubuntu release Natty Narwhal (11.04) just type the following command in a Terminal:

do-release-upgrade

Be shure to have enougth space in your hard drive. I had to free 2,8 GB for the new packages and upgraded from 10.10.

Firefox 4 for Ubuntu 10.04 and 10.10

sudo add-apt-repository ppa:mozillateam/firefox-stable
sudo apt-get update
sudo apt-get upgrade

How to convert CHM files into PDF files

There is a Python script called chm2dpf that converts CHM files into PDF files. To install it in Ubuntu use the follwing command:

sudo aptitude install chm2pdf

Using chm2pdf to convert a chm book:

chm2pdf --book my-file.chm my-file.pdf

Proxy support for apt-get package management

Define the http_proxy variable in the format http://host:port/. If you have to login then use the format http://username:password@host:port/. To define this variable add the following lines to the root login file /root/.bashrc.

http_proxy=http://username:password@host:port/
export http_proxy

To use the proxy only user specific define the variables in the file ~/.bash_profile or ~/.profile. If the file ~/.bash_profile exists the file ~/.profile will ignored by the Bash (Standard-Shell). The settings in ~/.bashrc overwrite ~/.profile, too.

To use changes of the file ~/.profile without a restart you can use the following command:

source ~/.profile

NVIDIA screen settings

Settings are saved in /etc/X11/xorg.conf and can be changed with

sudo nvidia-settings

The configuration file for nvidia-settings is ~/.nvidia-settings-rc and can be updated with

sudo nvidia-settings -r, --rewrite

With Intrepid Ibex and above the screen resulotion is not saved in xorg.conf but rather in the file ~/.config/monitors.xml.

Name of graphic card

lspci | grep -i vga

Assign a root password

To be able to log in as root directly, you must assign a root password. This can be done with:

sudo passwd root

Afterwards, you can use

su