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Written by Tony Phelps
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Tuesday, 15 August 2006 |
While most readers stick to a single computer running a single operating system (most commonly Microsoft Windows), one of the latest fads in the IT industry allows a single computer to run multiple operating systems – simultaneously or as needed. In fact, “virtualisation” allows a single computer to pretend to be many computers, not just run different operating systems.
Virtualisation is the technology of creating one or more virtual computers within a real one. So you might have a virtual Windows computer side-by-side with a virtual Linux computer. To all intents and purposes, each virtual computer is identical to a 'real' equivalent (ie. with its own dedicated hardware). Each virtual computer has its own virtual network card, its own virtual hard-disk etc., and you can use either one at any time as if it were installed on a separate physical computer.
So virtualisation allows you to magically create several computers using just one physical computer (the one you can kick). Why would you want to do this? Aside from the sheer glee of being able to use Windows XP at the same time as use Linux at the same time as use Windows 98 (there are people like that), there are practical benefits.
Virtualisation requires an underlying, or base, operating system. For example, you might download and install the free Ubuntu operating system. You could then download and install the free VMWare Server software which allows you to create up to four virtual computers – the VMWare software runs within the base Ubuntu. Using a web browser, you then connect to a VMWare webpage within the computer, and there build the virtual computers of whatever flavour you desire.
You could build your “production” virtual computer – the one you use for emails, web browsing, word processing, and any other tasks that you regularly perform. This one you would avoid messing about with as much as possible. Now say there is an upgraded version of some software you want to try, or some completely new software package. Simply take a 'snapshot' of your production virtual computer, and create a duplicate virtual computer. This duplicate is the same as the original in almost all respects – install your new software, and if it messes things up, just delete the duplicate virtual computer, no harm done. If the new software is OK, go ahead and install on your production virtual computer safe in the knowledge it has been tested.
The snapshot facility is also particularly useful for disaster recovery. A recurring difficulty in IT land is that it is very hard to rebuild a computer even if you have full backups. Buy a computer today and in three months you will not be able to get an exact replacement. This means changed hardware and therefore different drivers, licencing problems with software, etc. etc. But if you build your production system as a virtual computer, you can take a snapshot and store it (eg. on DVD) and be able to recreate exactly the same system within minutes on completely different hardware – the underlying virtualisation software makes it look like the hardware is always the same.
Virtualisation has drawbacks eg. it slows things down, but it is an interesting technology to be aware of. It may be what just what you need to keep one system going while also using a new one.
Questions & comments? Contact us - Merlin Pacific IT provide effective & efficient business IT. Discuss this or any other IT topic via email with VIGNET (Vanuatu Internet User Group) - register free at http://tinyurl.com/zcusl
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Last Updated ( Monday, 21 August 2006 )
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