Linux based virtualisation – the way to save money and go green

By David M Williams
Sunday, 13 July 2008 21:09

Technology

Virtualisation is a technology that can work wonders: provide a testing environment, enhance your processing power, consolidate your computing resources, decrease running costs, preserve legacy apps and more! Here’s how virtualisation can benefit you and why the Linux route really beats out the competition.



Virtualisation is all about running a pseudo-computer as if it were just another application running on a real computer. The virtualised computer believes it has a hard drive to itself; in reality its whole file system is merely contained within disk files on another underlying file system. The virtualised computer will act just as if it were physically installed on a computer from the outset, with the processor and resources to itself.

The virtual computer need not be the same operating system as the host it runs on. In fact, this is where virtualisation makes for an excellent test environment. You may be a Microsoft Windows user who has not yet switched to Linux. You can try out different Linux distros within virtual PCs on your computer. There’s no risk of harming your Windows installation but yet you still get the benefits of a real Linux deployment. Of course, it need not even be Linux you may be trialling. You may wish to try out Windows Server software on your Linux or Windows XP or Vista system. You can mock up a multi-server environment on a single computer by running more than one virtual PC with their own configurations.

The computer architecture does not even have to match. You can run a 32-bit virtual PC on a 64-bit computer. Here’s where support for legacy applications comes in. Perhaps you have an old Windows NT program your business must continue supporting. Yet, you don’t want to maintain a Windows NT computer. You might have shiny new servers running a much more contemporary server operating system. It doesn’t matter what is installed on them, nor if they are 64-bit machines. You can create a virtual 32-bit Windows NT environment for your legacy program to run on. It believes it really is running on such a computer, and you’ve totally removed the burden of retaining and maintaining old hardware.

Due to the fact file systems for virtual computers are just disk files within a parent environment you can easily back them up; it is merely a dead simple straightforward disk copy. This means you can swiftly make backups prior to implementing a change on the virtual PC. If things go wrong, no matter. Recovery is nothing more than closing the virtual machine, replacing the file system disk file with a backup copy and restarting. As far as the virtual computer is concerned absolutely nothing happened. Anything between making the backup and restoring it just did not take place.

Businesses have found value in virtualisation because of the opportunity it gave legacy applications to continue life without actually tying up a real computer. This in turn lead to the next big virtualisation virtue, namely server consolidation.

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