VirtualBox is the biggest cross platform, free virtualization solution available today. It can run multiple operating systems in virtual machines. Using VirtualBox, you can create a virtual machine that has its own BIOS, boot order priority, and you can install any Operating system in it. The virtual machine can be assigned CPU (in case of multiple CPUs), hard disk space, memory and it can have more than one network interfaces. The operating systems supported include Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7), DOS/Windows 3.x, Linux (2.4 and 2.6), Solaris and OpenSolaris, OS/2, and OpenBSD, though you can install most operating systems seamlessly.
Installation of VirtualBox
The installation of VirtualBox is pretty simple on an Ubuntu box. VirtualBox is included in the official repository of Ubuntu (and other Ubuntu based Linux distros such as LinuxMint). It can be installed with this simple command:
$ sudo apt-get install virtualbox-ose
Creating a virtual Machine
Open VirtualBox: Pressing alt+f2, type 'virtualbox' and hit return.
To create a new virtual machine, click new or press ctrl+n for "New Virtual Machine" wizard.
Hit 'Next' to move to next window.
This window asks for a name of the virtual machine. VirtualBox automatically guesses the operating system and its version based on the name you have provided. But if it does not guess right, you can provide it manually. Once the name is input, you can move to next screen.
You can select how much physical memory you want to allocate to your virtual machine and move to next screen.
This screen asks you to provide the hard disk to your virtual machine. You can select an existing hard disk image (virtual box disk) or create a new one.
If you create a new hard disk, you are welcomed with 'virtual disk creation wizard'. Select the file type here and if you are unsure, don't worry, let the default option selected.
In the details for virtual disk storage, you can choose to dynamically allocate the hard disk space. In this option, the hard disk space on your physical device will be filled as you start filling the virtual disk. The other option is the fixed size disk, which is faster to use and takes longer than dynamic disk creation.
You can type in the name of the hard disk and its location to save. Also, you can provide the hard disk size here.
Final screen provides the summary for the hard disk. Hit create button to create the virtual disk.
Back to the virtual machine creation wizard; it also shows the summary for the virtual machine. Again, hit ‘create’ to create the virtual machine.
Your virtual machine is ready to be used. When you run it first time, it asks you for the location of the installation CD for the operating system. Optionally, you can provide the iso file location. Now you can install the operating system the usual way.