VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License.

To install VirtualBox on Ubuntu you need to add its repository

echo 'deb http://download.virtualbox.org/virtualbox/debian precise contrib' >> /etc/apt/sources.list

You need to install apt-secure key for VirtualBox

cd /tmp/
wget http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc
sudo apt-key add oracle_vbox.asc

To install VirtualBox, do

sudo apt-get update
sudo apt-get install virtualbox-4.1 dkms

To run VirtualBox, Go to Application > System Tools > Oracle VM VirtualBox

In Microsoft Windows Administrator is the most powerful user, same way in linux there is a SuperUser named Root. Root can do anything and everything. Due to the same root can be dangerous in daily work. You can use sudo command to do most of the super user’s task.

By default, the root account password is locked in Ubuntu. I am writing this tutorial only for knowledge purpose. In production envioronment it is not recommended to enable root account.

To get started, open a new terminal and type following commands to create a new root password

sudo passwd root

Now run following commands to enable manual or other login

sudo sh -c 'echo "greeter-show-manual-login=true" >> /etc/lightdm/lightdm.conf'

Restart your computer and now you can choose to login as root user

GIMP (GNU Image Manipulation Program) is a multi-platform photo manipulation tool. The GIMP is suitable for a variety of image manipulation tasks, including photo retouching, image composition, and image construction.

GIMP has many capabilities. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc.

GIMP is expandable and extensible. It is designed to be augmented with plug-ins and extensions to do just about anything. The advanced scripting interface allows everything from the simplest task to the most complex image manipulation procedures to be easily scripted.

One of The GIMP’s strengths is its free availability from many sources for many operating systems. Most GNU/Linux distributions include The GIMP as a standard application. The GIMP is also available for other operating systems such as Microsoft Windows or Apple’s Mac OS X (Darwin). The GIMP is a Free Software application covered by the General Public License [GPL]. The GPL provides users with the freedom to access and alter the source code that makes up computer programs.

Today we will see how to install GIMP 2.8 on Ubuntu 12.04
Step 1 Open a command prompt

Step 2 Run following command to add gimp repository

sudo add-apt-repository ppa:otto-kesselgulasch/gimp

Step 3 To install GIMP run following commands

sudo apt-get update
sudo apt-get install gimp

You can also download the source package from here

By default Ubuntu Desktop OS comes with ssh client package. It does not include ssh server package which is needed to access this machine.

To install SSH on the newly installed Ubuntu 12.04 run following commands

sudo apt-get update
sudo apt-get install ssh

That’s it. To confirm the working ssh. Run the following commands from another machine

ssh username@IP_of_the_ubuntu_machine

If you get following error then
1. ssh is not running on the remote server
2. ssh is configured to run on different port

ssh: connect to host 192.168.1.10 port 22: Connection refused

Also remember to open ssh port between remote and host machine for communication.

Following the steps I followed to enable console boot in Ubuntu 12.04

Step 1 First update your repository by running

sudo apt-get update

Step 2 There is some bug in old version of lightdm, so we need to upgrade the same. To do so run,

sudo apt-get install lightdm

Step 3 Now we have to modify grub config.
Step 3a Open /etc/default/grub with your faviourite editor and change

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to

GRUB_CMDLINE_LINUX_DEFAULT="text"

Step 3b Also comment GRUB_HIDDEN_TIMEOUT=0 This line is for unhiding the GRUB menu

Step 4 Now we will upgrade GRUB configuration

sudo update-grub

Step 5 Now restart your machine. Voilla you will be in console mode

At any time you need after booting your system you want to change to gui mode the run

startx

If you want to restore Ubuntu’s GUI mode then

Open /etc/default/grub with your faviourite editor and change

GRUB_CMDLINE_LINUX_DEFAULT="text"

to

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Update GRUB by running

sudo update-grub

That’s it

I am not a big fan of Unity Desktop Environment. I still like GNOME. As with GNOME I feel more comfortable.

Every time with new installation I install GNOME classic Desktop Environment. GNOME Classic a.k.a GNOME Fallback is one i use instead of unity, and also which is arguably the most familiar to that of the Ubuntu desktop that shipped in Ubuntu 10.04 by default.

To install Gnome Classic open a terminal and run following commands

sudo apt-get install gnome-panel

Now restart your Desktop.

After restarting the Machine look for the GNOME Classic from the Unity Greeter and login.

For more such Ubuntu 12.04 tutorial stay tuned with Techienote.

To start accessing internet or sharing other resources on the network you have to configure TCP/IP settings of you ethernet card. In ubuntu you can configure network settings through GUI and CLI. It can be a difficult task for newbie user who is switching from other OS to ubuntu as the look and feel of ubuntu will be different in comparison of other OS (specifically windows). In this tutorial we will be seeing how to configure TCP/IP setting via GUI as well as CLI.

Before starting the configuration part, you have to know whether you will be configuring IP manually or IP will be assigned directly through DHCP server.

In case of manual IP assignment you should know IP address, subnet mask, gateway and DNS. In this tutorial I am using following information. Remember you don’t require it in case of DHCP configuration.

IP : 192.168.1.100
NETMASK : 255.255.255.0
GATEWAY : 192.168.1.1
BROADCAST : 192.168.1.255
NETWORK : 192.168.1.0
DNS : 8.8.8.8

Method 1 : Configure network GUI mode

Step 1 : First find out the network interface to configure. Open a terminal and run ifconfig

ifconfig

Result will be something similar to below screenshot.

Step 2 : We will be assigning IP address to eth0 adapter. To do the same Click on “System Setting” and select “Network”

Step 3 : As eth0 is wired connection click on “wired”. Choose “ON” option and click on “Configure” button.

Step 4 : Go to “IPv4 Settings” tab. In case of DHCP / Automatic configuration choose “Automatic (DHCP)” option in “method”

In case of manual configuration select “Manual” option in “method”. Click on “Add” button. Enter IP Address, netmask and gateway information. Also enter DNS Server. In this example I am using google DNS server’s IP.

After finishing it up click on “Save” button.

Step 5: To confirm the setting again run “ifconfig” command and check the “eth0″ interface settings. In case of successful configuration you will see something like below screenshot.

Method 2 : Configure network CLI Mode

Step 1 : First find out the network interface to configure. Open a terminal and run ifconfig

ifconfig

Result will be something similar to below screenshot.

Step 2 : We will be assigning IP address to eth0 adapter. Open a terminal and type

sudo vi /etc/network/interfaces

Step 3 : Now you need to add eth0 information in this file.
In case of DHCP / Automatic IP assignment enter following line and save this file.

iface eth0 inet dhcp

In case of manual IP assignment enter following line and save this file.

iface eth0 inet static
address 192.168.1.100
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.1

To configure DNS, enter following command. Remember to run it through “root” user

echo "nameserver 8.8.8.8" >> /etc/resolve.conf

Step 4 : Now run following command to start eth0 interface

sudo ifup eth0

Step 5: To confirm the setting again run “ifconfig” command and check the “eth0″ interface settings. In case of successful configuration you will see something like below screenshot.

For more such content stay tuned with techienote.

To host a website/web pages on your machine you need a webserver software. Apache http server is widely used http server in the world.

You can install apache http server through apt repository, but this will install all modules which I dont require to host a simple webpage. For the same I am going to compile apache http server 2.4.1 from source package.

Step 1 : Before installing apache you have to install necessary prerequisite libraries and software. To do so open your command prompt and run following

sudo apt-get update
sudo apt-get install build-essential

Step 2 : Downloading pre-requisites. I am downloading all the required software to /home/vidyadhar/install folder. Here we are downloading apache http server 2.4.1 source, apr / apr util source and pcre lib source. Open a terminal and run following commands

cd /home/vidyadhar/install
wget http://apache.mirrorcatalogs.com//apr/apr-1.4.6.tar.gz
wget http://apache.mirrorcatalogs.com//apr/apr-util-1.4.1.tar.gz
wget ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.30.tar.gz
wget http://apache.tradebit.com/pub//httpd/httpd-2.4.1.tar.gz

Step 3 : Extracting source. Open a terminal and run following commands

cd /home/vidyadhar/install
tar zxvf httpd-2.4.1.tar.gz
tar zxvf pcre-8.30.tar.gz
tar zxvf apr-util-1.4.1.tar.gz
tar zxvf apr-1.4.6.tar.gz

Step 4 : Installing PCRE to /home/vidyadhar/pcre folder. Open a terminal and run following commands

cd /home/vidyadhar/install/pcre-8.30
./configure --prefix=/home/vidyadhar/pcre
sudo make
sudo make install

Step 5 : Copying apr and apr-utils to srclib of apache http server. Open a terminal and run following commands

cd /home/vidyadhar/install/
mv apr-util-1.4.1 /home/vidyadhar/install/httpd-2.4.1/srclib/apr-util
mv apr-1.4.6 /home/vidyadhar/install/httpd-2.4.1/srclib/apr

Step 6 : Installing apache http server to /home/vidyadhar/apache2.4 directory. Open a terminal and run following commands

cd /home/vidyadhar/install/httpd-2.4.1
./configure --prefix=/home/vidyadhar/apache2.4 --with-included-apr --with-pcre=/home/vidyadhar/pcre
sudo make
sudo make install

Step 7 : If everything goes well you have a working setup of apache 2.4.1 http server working setup. Before starting the http server you have to do some changes in the http server configuration i.e. in httpd.conf file.

Step 8 : First we will take the backup of original file

cd /home/vidyadhar/apache2.4/conf
cp httpd.conf httpd.conf.orig

Step 9 : Now you need to adjust following parameters as per your requirement.
Listen port, User / Group who will be running apache demon, ServerAdmin, ServerName.
I am going to run apache http server through “nobody” user. For the same first you have to create nobody user and group.

sudo useradd nobody
sudo grouadd nobody

Now same user you have to configure in httpd.conf file

User nobody
Group nobody

Step 10 : I am having multiple nic card on my machine and as per the requirement I will be running http server on 8080 port. So my Listen and ServerName directive should be something like below

Listen 192.168.1.100:8080
ServerName 192.168.1.100:8080

Step 11 : Before starting http server you should always test your configuration. Run following command to check you configuration.

/home/vidyadhar/apache2.4/bin/apachectl -f /home/vidyadhar/apache2.4/conf/httpd.conf -t

The idle output of above command should be Syntax OK

Step 12 : Now we are ready start our http server. Run following command to start http server

/home/vidyadhar/apache2.4/bin/apachectl -f /home/vidyadhar/apache2.4/conf/httpd.conf -k start

Now open your browser and enter http://192.168.1.100:8080 in URL.

Remember in above URL 192.168.1.100:8080 is the IP and PORT on which my http server listening.

If your are unable to start apache http server check for the http server logs which are located at /home/vidyadhar/apache2.4/logs folder

I was little curious about Desktop Wallpaper Slideshow on Ubuntu. Previously I have configured it for Windows with the third party tool. In Ubuntu you can achieve this using CreBS (Create Background Slideshow). You can add this small application by modifying your sources.list file. More important, it is an open source software.

Installation

Step 1 : On Ubuntu Oneiric 11.10, add following entries in the sources.list

sudo vi /etc/apt/sources.list

Add following lines

deb http://ppa.launchpad.net/crebs/ppa/ubuntu natty main
deb-src http://ppa.launchpad.net/crebs/ppa/ubuntu natty main

Step 2 : Import the key

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EF0A4C44

Step 3 : To install CreBS run following commands

sudo apt-get update
sudo apt-get install crebs

Configuring / Creating Slideshow

Step 1 : Open Terminal and enter crebs. It will open a new slideshow configuration Windows.

Step 2 : Click the “+”” button to add wallpapers. After adding images you can click on the Slideshow tab to configure the length of the slideshow.

Step 3 : Enter a name for your slideshow and click the “Tick” button to save.

Activating the slideshow

To activate slideshow we have to do some setting manually.

Open a terminal and type

GSETTINGS_BACKEND=dconf gsettings set org.gnome.desktop.background picture-uri "file://$HOME/.crebs/techienote_s_slide_show.xml"

Replace “techienote_s_slide_show.xml” with the name of the slideshow that you have saved earlier.

That’s it.

As the Ubuntu 12.04 beta is out I thought I should give it a try. Currently I am using Ubuntu 11.04. So it is very simple task to Upgrade my current version to Ubuntu 12.04.

Before doing so I was having 3 options

Option 1 - Download ISO image from the ubuntu website and burn that into CD. Boot the cd and upgrade while installing into your machine which have earlier version of Ubuntu.

Option 2 - Make a Bootable flash drive to upgrade.

Option 3 - Use Update Manager.

As the easiest method I started upgrading my current OS using option 3.

Step 1 : Open a command propmt and run following commands

sudo apt-get update
sudo apt-get install update

Step 2 : Now start Update Manager using following command

sudo update-manager -d

Step 3 : It will ask for the passoword, provid the same. Now you should get the upgrade button on the right top.

Step 4 : Click on the Upgrade Button after confirming the upgrading it starts downloading the updates.

Step 5 : For downloading and upgrading my machine it took 45 minutes. The time limit depends on your internet connection.