Ubuntu

This page is dedicated to the Ubuntu Linux distribution or derivatives

References

• Ubuntu Documentation
  The same documentation is also available in Gnome / KDE Help
  • Ubuntu Server Guide - Ubuntu 10.04 LTS (or Help → Advanced Topics → Ubuntu Server Guide)
    Gold mine of information on how to run a server with Ubuntu (firewall setup, mail server, VCS setup...)

Repositories

• Ubuntu Repositories — Examples for Lucid distribution:

#Stable repository
deb http://be.archive.ubuntu.com/ubuntu/ lucid main restricted universe multiverse
deb-src http://be.archive.ubuntu.com/ubuntu/ lucid main restricted universe multiverse

#Distribution security updates
deb http://be.archive.ubuntu.com/ubuntu/ lucid-security main restricted universe multiverse
deb-src http://be.archive.ubuntu.com/ubuntu/ lucid-security main restricted universe multiverse

#Distribution updates
deb http://be.archive.ubuntu.com/ubuntu/ lucid-updates main restricted universe multiverse
deb-src http://be.archive.ubuntu.com/ubuntu/ lucid-updates main restricted universe multiverse

#Partner repository
deb http://archive.canonical.com/ lucid partner
deb-src http://archive.canonical.com/ lucid partner

• Ubuntu Backports
  Provides backports (i.e. new versions of applications from newer distribution re-packaged for the current distribution) of specific applications (like Amarok) on request.

deb http://be.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
deb-src http://be.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse

• ppa:kernel-ppa/ppa
  Provides kernel backport candidates before making them available in the updates or security repositories.
  The usual add-apt-repository does not work. Instead create file /etc/apt/sources.list.d/kernel-ppa.list:

deb http://ppa.launchpad.net/kernel-ppa/ppa/ubuntu lucid main
deb-src http://ppa.launchpad.net/kernel-ppa/ppa/ubuntu lucid main

gpg --keyserver keyserver.ubuntu.com --recv A8267963484B044F
gpg --export A8267963484B044F | sudo apt-key add -

Other repositories:

• Midnight Commander official repository
• Ubuntu Tweak
• Medibuntu
• gitg

Install

Create an USB Startup disk

• Using Ubuntu Startup Disk Creator, one can create easily an USB startup disk (for any release, not just the same as the one used to create the startup disk)

Net boot install from Internet using GRUB

Reference: here

• Copy files initrd.gz and linux from one of the repository below to /boot
  • Ubuntu 10.10 Maverick Meerkat amd64
  • Ubuntu 10.04 LTS Lucid Lynx amd64 or i386
  • Ubuntu 10.04 Karmic Koala amd64
  • Ubuntu 9.04 Jaunty Jackalope amd64
• Restart, and type in GRUB command-line (press c in GRUB menu):

root (hd0,6)                         # Select partition where /boot is. Type "root (hd0," and then TAB to get a list of partitions
linux /boot/linux                    # ... or kernel /boot/linux for GRUB 1
initrd /boot/initrd.gz
boot

Net boot install from USB drive

This technique allows for very fast setup of a USB drive that can then be booted to start installation from network (Reference [1])

• Download the image boot.img.gz
  • Ubuntu 10.10 Maverick Meerkat amd64
• Plug in the USB, and unmount it if necessary.
• The boot image is already pre-configured as a USB drive. Uncompress it to USB device (not partition!):

zcat boot.img.gz >/dev/sdb

Net boot from within Windows

This technique allows launching a network boot install without the need of CD or floppies. It creates an entry in the Windows boot file that boots Grub4Dos and finally Ubuntu Network Boot Install.

See InstallFromWindows for more information.

1. Create a folder C:\boot
2. Download linux and initrd.gz from http://archive.ubuntu.com/ubuntu/dists/lucid/main/installer-i386/current/images/netboot/ubuntu-installer/i386/, and save them in C:\boot

Next, for Windows XP:

1. Download https://passechambre.appspot.com/get/grubfordos041pre22.tar.gz
2. Extract grldr from the archive to C:\
3. Create a new folder C:\boot\grub
4. Extract menu.lst from the archive (found in folder /boot/grub) to C:\boot\grub
5. Edit file c:\boot.ini, and append the line:

c:\grldr="Install Ubuntu"

1. Edit the file c:\boot\grub\menu.lst, and append the lines:

title Install Ubuntu
kernel   (hd0,0)/boot/linux vga=normal ramdisk_size=14972 root=/dev/rd/0 rw --
initrd   (hd0,0)/boot/initrd.gz

1. Reboot the PC, then first select Install Ubuntu from the windows boot menu, and finally Install Ubuntu from Grub menu.

Troubleshoot

error 19 : cannot mount selected partition

• If you get the error above after selecting Install Ubuntu from Grub, this is probably because your Windows primary partition is not on (hd0,0) (a frequent cause for this is that the the first partition is used by the BIOS as an OEM rescue partition). To find which partition to use, go back in the Grub menu, then press c to go to the Grub command line. Then type:

 kernel (hd0,TAB

When pressing TAB, Grub will propose a list of possible partitions. Try to identify your windows primary partition from the list (usually the first ntfs partition). You can then either restart the PC, boot windows normally and edit the file menu.lst, or simply type the lines directly in the command line (e.g. assuming your windows partition is in (hd0,1)):

kernel   (hd0,1)/boot/linux vga=normal ramdisk_size=14972 root=/dev/rd/0 rw --
initrd   (hd0,1)/boot/initrd.gz
boot

Administration

Add a new Launchpad PPA repository

use add-apt-repository to add a new launchpad repository

sudo add-apt-repository ppa:kernel-ppa/ppa

Ubuntu Tweak

To install Ubuntu Tweak:

sudo add-apt-repository ppa:tualatrix/ppa
sudo apt-get update
sudo apt-get install ubuntu-tweak

Kernel

• The Ubuntu Kernel Wiki (kernel archive)
• The Ubuntu kernel ppa (contain only very latest kernels)

Install new kernels

There are several sources for kernel on Ubuntu:

• The stable repository
• The security / updates repositories
  Updates of kernel from stable, but also stable backports
• The kernel PPA repository
  Proposes backports before making them available in security / updates repositories.
• The Ubuntu kernel archive at http://kernel.ubuntu.com/~kernel-ppa/mainline/.

To install a new version of the kernel:

• Choose manually the kernel version to install. You need to install the headers and the image, for instance:

sudo apt-get install linux-headers-2.6.32-28-generic-pae
sudo apt-get install linux-image-2.6.32-28-generic-pae

Note that you might need to install one of the additional repository above if the version you request is not in your current set of repositories.

• Install one of the meta-packages (See linux-meta) linux-* and linux-headers-*. These always points to the latest kernel versions so that you will always receive all security/serious bug updates.

sudo apt-get install linux-headers-generic-pae linux-generic-pae  # Generic PAE (for >=4GB systems)
sudo apt-get install linux-headers-generic     linux-generic      # Generic
sudo apt-get install linux-headers-virtual     linux-virtual      # For Virtual machine
sudo apt-get install linux-headers-server      linux-server       # For server
sudo apt-get install linux-headers-rt          linux-rt           # For RT kernel
sudo apt-get install linux-headers-generic-pae linux-generic-pae  # Generic PAE (for >=4GB systems)

• Install one of the LTS backport kernels linux-image-*-lts-backport-* and linux-headers-*-lts-backport-*. These are kernel metapackages from new distribution releases that always point to the latest kernel in that release so that they are automatically updated when there is a serious kernel bug fix. For instance, on Lucid:

# Maverick backport
sudo apt-get install linux-headers-generic-pae-lts-backport-maverick linux-generic-pae-lts-backport-maverick
# Natty backport
sudo apt-get install linux-headers-generic-pae-lts-backport-natty linux-generic-pae-lts-backport-natty

These backports are available in security or updates repositories, or in the kernel PPA.

• We can see easily dependencies between linux packages with commands:

apt-rdepends -d linux-image-generic-pae | dot -Tpng | display
apt-rdepends -rd linux-image-generic-pae | dot -Tpng | display

We can see that (at time of writing) that server kernels are actually synonyms for generic-pae kernels. We have indeed:

• Generic Linux kernel image: linux-imager-server points towards linux-image-generic-pae
• Generic complete Linux kernel : linux-server points towards linux-generic-pae

Remove old kernels

To remove old kernel entries in GRUB ([2] and [3], or other sol [4])

sudo apt-get remove --purge 2.6.28-11-*     #to remove kernel 2.6.28-11
sudo apt-get purge 2.6.28-11-*              #equivalent

An even easier solution is to install Ubuntu Tweak, and select Package Cleaner → Clean Kernels.

Devices

To see information on all connected input devices:

cat /proc/bus/input/devices

I: Bus=0003 Vendor=0c16 Product=0002 Version=0110
N: Name="Gyration Gyration RF Technology Receiver"
P: Phys=usb-0000:00:06.1-1/input0
S: Sysfs=/devices/pci0000:00/0000:00:06.1/usb3/3-1/3-1:1.0/input/input7
U: Uniq=
H: Handlers=kbd event7 
B: EV=10001f
B: KEY=837fff 2c3027 bf004444 0 0 1 c04 a27c000 267bfa d941dfed e09effdf 1cfffff ffffffff fffffffe
B: REL=40
B: ABS=1 0
B: MSC=10

Medibuntu

• Medibuntu home page
• Medibuntu community

To install the Medibuntu repositories (see Community or here)

sudo wget http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list --output-document=/etc/apt/sources.list.d/medibuntu.list
sudo apt-get -q update
sudo apt-get --yes -q --allow-unauthenticated install medibuntu-keyring
sudo apt-get -q update

Troubleshoot

CIFS shares not properly unmounted during shutdown

When shutting down the PC with Samba (CIFS) shares mounted, the shutdown sequence hangs with the following error messages:

CIFS VFS: server not responding
CIFS VFS: no response for cmd 50 mid xxx 

This is apparently a bug that is creeping in Ubuntu since a long time ago. Basically there are 2 possible fixes (as in [5], [6], [7]):

The one I use, proposed by Daniel Ellis here [[8]]:

sudo mv /etc/rc0.d/S31umountnfs.sh /etc/rc0.d/K31umountnfs.sh
sudo mv /etc/rc0.d/S40umountfs /etc/rc0.d/K40umountfs
sudo mv /etc/rc6.d/S31umountnfs.sh /etc/rc6.d/K31umountnfs.sh
sudo mv /etc/rc6.d/S40umountfs /etc/rc6.d/K40umountfs

Another one (not tried yet):

sudo ln -s /etc/init.d/umountnfs.sh /etc/rc0.d/K15umountnfs.sh
sudo ln -s /etc/init.d/umountnfs.sh /etc/rc6.d/K15umountnfs.sh