If any of the output runs off your screen, just add |more to the end of any of these commands to see the output one screen at a time and hit the spacebar to go to the next screen, or Q to quit.

Processor type:
$ cat /proc/cpuinfo

Is the processor using 32 or 64 bit instruction set:
$ cat /proc/cpuinfo | grep flags | grep lm
If you get some output you have a 64 bit CPU. If you receive no output, then you’re using a 32 or even 16 bit CPU. The reason this is the case is that the CPU yields many flags that tell Linux what sort of processor it is, and the lm flag informs Linux that the CPU is a 64 bit processor. Grep as a command filters output. Feel free to run this command without the grep suffixes (cat /proc/cpuinfo) to see the full output of your CPU details.

What hardware (audio, video, disk controllers, etc) is in my Linux box:
$ lspci -tv
(The -t switch groups similar devices together for easy reading and -v offers more verbosity.)

To easily filter out the above command to just show graphic card information:
$ lspci | grep VGA

What USB devices are plugged in:
$ lsusb

Check the size of the hard drive and what hard drives are available in the system.
This command will also list USB drives and sticks. You need a root permissions to execute the fdisk command:
$ sudo fdisk -l | grep GB

Show info about a particular hard disk including firmware revision (replace sda with the appropriate drive as listed from the above command):
Note: This will only work on internal disks, NOT USB drives.
$ sudo hdparm -i /dev/sda

Check what partitions and file system is in use on my hard drives (same as the above command, but essentially more verbose):
$ sudo fdisk -l

Locate CD/DVD-ROM device file which offers a CD/DVD-ROM’s make and model info:
$ wodim –devices
or
$ wodim –scanbus
The above command will scan your entire system bus for attached devices (this won’t include USB Devices as they are not direct-bus-attached devices).

What modules are currently loaded:
$ lsmod

get a information about any particular module:
$ modinfo module_name

remove modules:
$ modprobe –remove module_name

load a modules to the kernel:
$ modprobe module_name

What hardware is using which module.
The -v switch is for vebosity, where -vvv is EXTRA verbosity.
$ lspci -v
or
$ lspci -vvv

Check for PCMCIA cards:
$ lspcmcia

How much RAM is installed in my Linux and how much of it is in use (megabytes).
It will also include swap memory:
$ free -m
There is a gigabyte switch, but it *rounds* it down, so it isn’t very accurate for RAM info:
$ free -g

Check sound card settings. This command will reveal whether your sound card is installed and what modules are in use:
$ cat /dev/sndstat

Available wireless cards:
$ iwconfig

What speed is set to FANs:
$ cat /proc/acpi/ibm/fan
If this command doesn’t work, then feel free to peruse the /proc/acpi directory on your system. You will find info available on your CPU, AC Adapter, Battery, etc. Some info is available here, and your mileage may vary for viewing any of the files in /proc/acpi.

Get a battery information on your laptop (assuming it’s been installed):
$ powersave -b

To find out what Linux Kernel you’r running:
$ uname -a

To find out what distribution of Linux you’re running:
Run any of these commands, as depending on your distribution some may or may not work.
$ cat /etc/issue
$ cat /proc/version
$ dmesg | head -1

Get a recent history of system reboots:
$ last reboot

To open any file from command line using the default application (will launch the correct graphical application for the file, as though you had doubled-clicked the file graphically):
$ xdg-open ./filename

To monitor all active network connections, and update live every second:
$ watch -n.1 ‘netstat -tup’

To passively list all connections, active or inactive:
$ ‘netstat -tupl

(Launchpad link):

A dynamic tunnel SSH multiplexer. When heavily using a Dynamic SSH tunnel, this application will open concurrent SSH tunnels to multiplex the load. This is useful when using torrent connections locally, or when using your computer to share internet access via the dynamic proxy.

To install on Ubuntu Karmic:

sudo add-apt-repository ppa:martineve/ppa

sudo apt-get update

sudo apt-get install sshsplit

If no arguments are passed, you can run sshsplit from command line and it will bring up a convenient GUI for on the fly configuration.

Ubuntu is running an application called “landscape-common”.

More on this application here. The easy thing to do here is to simply type update-motd – -disable and you can then modify your MOTD. Also I have noticed that sometimes, the contents of motd.tail will overwrite the MOTD, so I would simply make sure whatever you want in /etc/motd is also in /etc/motd.tail. [On Debian systems, the system message of the day is rebuilt at each startup. /etc/motd.tail is the file to edit permanent changes to the message of the day].

Simply sudo apt-get install cpulimit. More info can be found here.

Using GNOME

• Get to the System->Preferences->Keyboard menu.
• Select the “Layouts” tab and click on the “Layout Options” button.
• Then select “Key sequence to kill the X server” and enable “Control + Alt + Backspace”.

Click the link below for the full article and how to do it in KDE.

Source: Ubuntu Geek.

People sometimes have to do a reinstall of their Ubuntu system for various reasons (been playing/experimenting with configuration/drivers/other packages or just because something is badly broken) but remembering all the extra packages you have installed can be a chore – but here is the simple solution:
On your old system (assuming it is still working), start up Synaptic and go to:

File-Save Markings and choose a file name along with a location (like a USB drive) that you can use when you have installed your new system)

This file contains a list of all your currently installed packages, and when you have installed and booted up your new system (and configured your repositories to the best for your location ) then start up Synaptic and go to:

File-Read Markings and point it at your saved file, and after that has completed then select Apply to kick off the download & installation of all of those packages you had installed previously!

There are also apt-get command line functions that achieve the same outcome, so those who don’t have/use Synaptic can still do this.

You will still have to do any special configuration changes that you had on the old system, but at least all of the packages are now in the new system.

This is also very handy for moving to new hardware/duplicating setups etc.

Be aware that doing this between different Ubuntu versions may cause complications because some packages may not be in a later version or have different names.

Note:- Don’t forget to backup your sources before you reinstall.

sudo cp /etc/apt/sources.list ~/sources.list.backup

Otherwise if you have added any PPAs or other sources, this tip won’t work.

Bonding is creation of a single bonded interface by combining 2 or more ethernet interfaces. This helps in high availability and performance improvement.

How to setup dual-dual bonding (two bonds of two interfaces each) on Ubuntu as quickly as possible.

1. Add two lines to /etc/modules

bonding bond0 -o bond0 mode=1 miimon=100

bonding bond1 -o bond1 mode=1 miimon=100

If you’re very good at managing your time, just remember that miimon’s option determines how often the bond is monitored for failure and that mode can be one of:

0 – Round robin balancing

1 – Active back-up

2 – Transmit based on MAC address for load balancing/fault tolerance

3 – Broadcasting – provides fault tolerance by transmitting on all slave interfaces

4 – Aggregates links, assuming all nics support same speeds and duplex settings

5 – Transmit load balancing – balancing is handled by the bond based on load

6 – Same as 5, but also uses arp to balance load “better

2. Install the ifenslave package if you haven’t already. You can use apt-get to grab it if you don’t:

sudo apt-get install ifenslave-x.x

3. Ensure that the package actually installed:

sudo dpkg –get-selections | grep enslave

ifenslave-x.x install

4. Set up your interface files:

# cat /etc/network/interfaces (only including the parts you probably need – substitute IP addresses, netmasks, etc):

auto lo

iface lo inet loopback

auto bond0

iface bond0 inet static

address 10.10.125.88

netmask 255.255.255.0

network 10.10.125.0

gateway 10.10.125.1

post-up ifenslave bond0 eth0 eth2

pre-down ifenslave -d bond0 eth0 eth2

auto bond1

iface bond1 inet static

address 10.10.127.88

netmask 255.255.255.0

network 10.10.127.0

gateway 10.10.127.1

post-up ifenslave bond1 eth1 eth3

pre-down ifenslave -d bond1 eth1 eth3

5. Add lines to the bottom of your architecture’s modprobe files, reboot
and pray:

sudo cat /etc/modprobe.d/arch/i386

alias bond0 bonding

options bond0 mode=1 miimon=5000 max_bonds=2

alias bond1 bonding

options bond1 mode=1 miimon=5000 max_bonds=2

I am not sure if the anti-virus recommendation is required at this time, I think that might be overkill, but if you intend to use the system in a live production environment, it’s all worth considering.

One of the most common mistakes is not checking log files (reason #10). I often find it hard to keep up and sometimes parse the variety of system logs on a system. A great tool for managing this is called LogWatch. While not a GUI, it summarizes system logs into a convenient report that you can cron to run regularly and email to yourself, or just monitor. It’s highly configurable with varying degrees of detail.

From the site:

Logwatch is a customizable log analysis system. Logwatch parses through your system’s logs for a given period of time and creates a report analyzing areas that you specify, in as much detail as you require.

Likewise Open is a free, open source application that joins Linux, Unix, and Mac machines to Microsoft Active Directory and securely authenticates users with their domain credentials.

The GNU MP3/Media Streamer is a simple application which makes it possible to navigate through your audio and video collection via a browser, and stream playlists across a network.GNUMP3d is a streaming server for MP3s, OGG vorbis files, movies and other media formats.The software supports browsing, searching, and streaming all via your browser with support for MP3, OGG Vorbis, WMA and many other types of audio files.

Click here for more info and configuration information.

GnuMP3d home site.

Here’s the full howto.

HOW TO’s:

Ubuntu Studio 8.04 Desktop:

Ubuntu Studio 8.04 Server:

–

Ubuntu Studio homepage:

SUN announced that they’re going to further certify their servers with Ubuntu Linux. At this time there’s no plans to release Hardy Heron (8.04) for the SPARC processor, though SUN will be certifying their x86 line of servers with Ubuntu, and their more of their SPARC servers with earlier versions of Ubuntu which have been released for SPARC processors.

At Ubuntu Live, expect SUN to announce how MySQL, OpenOffice and Ubuntu will evolve with SUN to meet customers’ needs.

Sources: One, Two.

From the andLinux site:

andLinux is a complete Ubuntu Linux system running seamlessly in Windows 2000 based systems (2000, XP, 2003, Vista [32-bit only]). This project was started for Dynamism for the GP2X community, but its userbase far exceeds its original design. andLinux is free and will remain so, but donations are greatly needed.

andLinux uses CoLinux as its core which is confusing for many people. CoLinux is a port of the Linux kernel to Windows. Although this technology is like VMware or Virtual PC, CoLinux differs itself by being more of a merger of Windows and the Linux kernel and not an emulated PC, making it more efficient. Xming is used as X server and PulseAudio as sound server.

andLinux is not just for development and runs almost all Linux applications without modification.

Click here for a sample screenshot.

Also, an excellent article on the subject from Lifehacker.