Virtualisation guide

With the right software, you can get two computers for the price of one.
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  • Updated:18 Sep 2008

03.Application virtualisation

In fact, It’s likely that your computer already runs some kind of virtualisation. Most web browsers, for example, are Java-enabled. Java is a programming language used to create online games, embedded chat, bank logins and other interactivity on websites. But Java needs to use the same instructions whether it’s running on a Mac, Windows or Linux.

To do that, it runs what’s called the Java Virtual Machine, an isolated layer which separates it from the rest of the operating system. From there, it can ask permission to use portions of the operating system if it needs to, such as to start a chat session or to create and manage a pop-up keyboard for online banking. Java is an example of application virtualisation — a single application is kept isolated from the rest of the operating system.

Java has been around for ten years, and application virtualisation isn’t new. But recently, it’s been used more widely. Some newer antivirus and internet security software, such as ZoneAlarm Forcefield by Checkpoint Software, is using virtualisation to create a ‘test bed’. The test bed is used to investigate software that your browser downloads from the Internet. ForceField checks whether it performs any malicious operations, whether it will hijack your email software to send out spam or make copies of itself, or whether it will intercept your system’s Internet connection to spread. By mimicking aspects of your system using virtualisation, the test bed checks that the software is safe, and at the same time runs it within a completely isolated section of computer. If anything bad happens, it won’t affect the rest of your system.

Virtualisation and you

Virtualisation offers a lot of potential, but how can you make use of it for your home computer? There are number of scenarios where you might find it useful:

  • To run software requiring an older version of Windows
  • To explore new operating systems such as Linux
  • To trial software in a safe environment before using it
  • To run two or more operating systems at the same time

Indeed installing a program in a virtual machine guest before installing it on the host machine is a great way of seeing how the program runs, what changes it makes to your desktop or operating system, or if it has any malicious software inside. No matter what happens inside the guest machine, it’s completely separate and secured from the host. And as soon as you close the guest machine, everything inside ceases to exist.

This process is known as sandboxing, and while not everyone will always want to spend time setting up a guest machine just to test out software, there are real advantages to setting up a guest machine with an alternative operating system that has applications you want to use — especially legacy software, for example programs that run under Windows XP better than under Windows Vista, but you have Vista installed because it came with the machine. Here keeping a separate computer just to run Windows XP would be overkill — but with virtualisation you don’t need to. All you need to do is create a guest machine using virtualisation software and install Windows XP into it, and load it when you need it

Software for virtualisation

So what virtualisation packages can you use to create virtual machines on your system? There are several free or low cost options:

  • VirtualBox by Innotek and released by Sun Microsystems is cross-platform for Windows, Mac and Linux, and completely free. While it assumes some level of knowledge with respect to virtualisation, it’s still easy to set up and run virtual machines. It also makes it easy to set up ‘shared folders’ between a guest machines and the host, making it simple to transfer files between them.
  • VMWare produces a product called VMWare Workstation (US$189) that lets you create and run virtual machines, and it has a free companion product called VMWare Player that can’t create virtual systems, but can run them. VMWare hosts a site packed with prepared virtual systems, which includes many Linux distributions and other operating systems that don’t need end user licenses. Like VirtualBox, VMWare can be installed and run under both Windows and Linux (indeed, the first versions of VMWare were a Linux only product).
  • Virtual PC 2007 is virtualisation software from Microsoft allows drag and drop copying between the virtual computer and the base operating system through shared folders. Virtual PC used to be a commercial product, but Microsoft (possibly in light of competition) has now made it completely free to download and use. Naturally, Virtual PC is available only for Windows. There are other alternatives, but these are the big three and the easiest to use. For the Mac platform popular choices include Parallels and VMWare.

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