Ubuntu notes

This page is a very terse distillation of things I've had to fiddle with. Most of these solutions have come from wading through Ubuntu Forums.

Enable Sensible Repositories

A vaguely useful apt sources.list:

 deb     http://nz.archive.ubuntu.com/ubuntu/ hardy          main restricted universe multiverse 
 deb-src http://nz.archive.ubuntu.com/ubuntu/ hardy          main restricted universe multiverse 

 deb     http://nz.archive.ubuntu.com/ubuntu/ hardy-updates  main restricted universe multiverse 
 deb-src http://nz.archive.ubuntu.com/ubuntu/ hardy-updates  main restricted universe multiverse 

 deb     http://security.ubuntu.com/ubuntu    hardy-security main restricted universe multiverse 
 deb-src http://security.ubuntu.com/ubuntu    hardy-security main restricted universe multiverse 

 deb     http://archive.canonical.com/ubuntu  hardy          partner 

 deb     http://medibuntu.org/repo/ hardy free non-free 
 deb-src http://medibuntu.org/repo/ hardy free non-free 

Note: Can replace security.ubuntu.com with nz.archive.ubuntu.com for faster transfers, with slightly less up-to-date-ness.

One Line APT Keys command

Medibuntu requires its GPG key:

sudo apt-key advanced --keyserver subkeys.pgp.net --recv 2EBC26B60C5A2783

Connect to a Windows VPN

Finally, some clever Ubuntu Gnome folks have written a network manager plugin for doing Windows VPN connections over PPTP. The extremely cool network manager is also available for KDE:

sudo apt-get install network-manager-pptp network-manager-kde

Crazy Wireless Drivers

If you are lucky enough to have bought a HP or Compaq laptop recently, you've probably got a Broadcom wireless chipset. Broadcom are lazy wankers and don't release their driver code.

Solution (before 8.04): Use ndiswrapper 1.8. Blacklist the built-in bcm43xx and download these Win32 Broadcom 4318 drivers.

sudo apt-get install ndiswrapper-utils-1.8 ndiswrapper-common

ATI Radeon Xpress 200M

Works in 8.04. In earlier versions, getting this chip to do 3D reliably is a pain in the arse. The fglrx driver does not work with Linux on laptops with the ATi Radeon Xpress 200M unless the BIOS is changed to use Sideport + UMI set to 128 MB. LAME.

Current Recipe

Get the latest Debian module building tools with this incantation:

sudo apt-get install module-assistant build-essential fakeroot dh-make
sudo apt-get install debhelper debconf libstdc++5 linux-headers-$(uname -r)

Download the latest ATI driver binary and tell it to build Ubuntu packages, then install them:

bash ati-driver-installer-8.34.8-x86.x86_64.run --buildpkg Ubuntu/edgy
sudo dpkg -i *fglrx*8.34.8*.deb

Get the module assistant to build and install the fglrx kernel module thus:

sudo module-assistant prepare
sudo module-assistant update
sudo module-assistant build fglrx
sudo module-assistant install fglrx
sudo depmod -a

Configure your X server (or edit /etc/X11/xorg.conf by hand):

sudo aticonfig --initial
sudo aticonfig --overlay-type=Xv

and make sure you have this in xorg.conf as well:

Section "Extensions"
    Option  "Composite" "Disable"
EndSection

See also

Getting the laptop ATI 200M chipset to play nice with the plasma telly, and getting the NVidia 8800GT to work at all with gutsy.

SSH Authentication With Keys

Turn off ssh login prompts and do everything with keys. This will reduce the attack surface on port 22. First, create a key using the following command:

ssh-keygen -t dsa -f ~/.ssh/mykey

This will ask for a pass-phrase and create a pair in your .ssh directory as two files, mykey containing the private key and mykey.pub containing the public key. Then for each host you log in to, scp your public key to your home folder and append it to the ~/.ssh/authorized_keys file, thus:

me@home$ scp ~/.ssh/mykey.pub me@remotehost:~
me@home$ ssh remotehost
Password: 
me@remotehost$ cat ~/mykey.pub >> ~/.ssh/authorized_keys

Then, in your Gnome Sessions configuration under Startup Programs, add this:

ssh-add /home/me/.ssh/mykey 

Note that you will need your full home path, not the ~ shortcut. Now, you can enter your pass-phrase once at the start of every session, and log in to your hosts without prompting for passwords. Once you have it working, you can then disable ssh password prompts.

References

• Ubuntu Forums