Just some notes on useful Ubuntu tweaks

Settings

Gnome 3

  • Set workspaces to use both monitors - install gnome-tweak-tool and, under “Workspaces”, change “Workspaces only on primary display” (source).

Packages

  • General stuff: sudo apt-get install git emacs24 autocutsel openjdk-7-jre openssh-server texlive-latex-base texlive-latex-recommended pandoc nautilus-open-terminal
  • Python: sudo apt-get install python-scipy python-matplotlib python-numpy python-pandas python-pip ipython ipython-notebook pyflakes
  • Stuff which is rather out of date in the Ubuntu repos:
    • sudo pip install cython
    • sudo pip install -update pandas (or, if you want the dev version, do pip install -e git+git://github.com/pydata/pandas.git#egg=pandas)

  • I used to use pip to install stuff but you have to install lots of build dependencies which takes up hundreds of megabytes of space, plus pip doesn’t automatically keep your system up to date, unlike aptitude. Here’s what I used to do:

    • sudo pip install numpy
    • sudo apt-get install libpng-dev libjpeg8-dev libfreetype6-dev python-gtk2-dev (required for pip install of matplotlib); or do sudo apt-get build-dep matplotlib
    • sudo pip install matplotlib
    • sudo pip install pandas
  • Ubuntu restricted extras (enables playback of Coarsera videos in Chromium)

Files and directories to back up before doing a re-install

  • /data/
  • /home/jack/  (make sure to copy all the hidden files like .bashrc)

Directory shortcuts

Use case: from the command line, you want a quick and easy way to jump to frequently used directories.

Method one: use the source operator.  For example, I want a shortcut to ~/Documents/imperial/PhD. So I create a file called p which just contains the text cd '~/Documents/imperial/PhD'.  On bash I type . p to execute the code in the file (if I used a bash script then the change directory would only affect the script and would not be persistent when the script terminates).  csh doesn’t have a “.” operator.  Instead you have to type “source p”.  Or alias . to source by adding the linealias . 'source' to ~/.cshrc

Method two: just add an alias to change directory.  e.g. add alias p 'cd ~/Documents/imperial/PhD  to ~/.cshrc

Network Time Protocol client

To set up NTP, I followed the instructions here.  I commented out the lines in /etc/ntp.conf for Ubuntu’s own NTP servers and instead used ntp.plus.ne,  ntp2d.mcc.ac.uk and ntp2c.mcc.ac.uk (mcc.ac.uk is Manchester University).  There’s an (out of date) list of public NTP servers here (using sandvika.net gives a “host name not found” error) and a longer list here.

Permenantly disable a kernel module (without recompiling)

add “blacklist MODNAME” to/etc/modprobe.d/blacklist-local.conf.  e.g. “blacklist ums_realtek” (note that a newline is required after the module name) (which was required to stop “Assuming drive cache: write through” on my Lenovo S10e netbook (running Ubuntu 12.04 server)). Blacklist info found on serverfault; removing ums_realtek to fix problem on netbook found on bugs.launchpad.

CPU frequency

sudo apt-get install cpufrequtils
cpufreq-info

Temperatures

sudo apt-get install acpi
acpi -V

Battery 0: Full, 100%
Battery 0: design capacity 2808 mAh, last full capacity 1996 mAh = 71%
Adapter 0: on-line
Thermal 0: ok, 55.0 degrees C
Thermal 0: trip point 0 switches to mode critical at temperature 86.0 degrees C
Thermal 0: trip point 1 switches to mode passive at temperature 80.0 degrees C
Cooling 0: LCD 0 of 10
Cooling 1: Processor 0 of 10
Cooling 2: Processor 0 of 10

System info display when you SSH into a machine

To get this displayed when you SSH into a machine:

~/$ ssh vaio
jack@vaio's password: 
Welcome to Ubuntu 12.04 LTS (GNU/Linux 3.2.0-27-generic i686)

 * Documentation:  https://help.ubuntu.com/

  System information as of Fri Aug 10 11:19:02 BST 2012

  System load:  0.63              Processes:           72
  Usage of /:   6.6% of 19.83GB   Users logged in:     1
  Memory usage: 11%               IP address for eth0: 192.168.1.64
  Swap usage:   0%

  Graph this data and manage this system at https://landscape.canonical.com/

Run sudo apt-get install landscape-common update-motd

Compiz with Unity-2D

Intalling Ubuntu 12.04 on a circa-2004-computer with an nVidia GeForce PCX 5300, I noticed that Compiz was disabled by default. After lots of messing around with uninstalling and re-installing compiz, I stumbled across the following thread: How to run Compiz on Unity-2D. I then had to fix some of my settings, especially re-enabling dBus and animations and window decorations.

Counting files and directories

  • ls -1 <DIR> | wc -l count files and directories in <DIR>
  • find <DIR> -type d | wc -l recursively count all directories below <DIR>
  • find <DIR> -type f | wc -l recursively count all files below <DIR>