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

David M Williams
Sunday, 13 July 2008 22:09

Business IT - Technology

After all, if you can avoid having to maintain old hardware for an outdated platform by running that system within a virtual PC there’s no reason you can’t avoid maintaining new hardware by continuing to virtualise your systems.

Using virtualisation you can combine multiple workloads all on the one physical computer. This equates to fewer actual machines although the overall work performed, and the number of environments represented, is not diminished in any way.

To appreciate the importance of this consider medium to large companies that have data centres with racks and racks of servers. Each one of these is performing a task of some sort. One may be a print server, another a mail server, several would be dedicated to a range of applications including small rarely-used apps that are only required by one person, a situation that all companies find they have acquired.

Every one of these computers is taking room. They are drawing power. They require cooling. There is a cost to all this. Now, hold that thought. Imagine now the hapless systems admin when the business comes along and advises they’ve now purchased their umpteenth special-purpose piece of software which seemingly always needs, say, a web server not tied up for any other purpose.

The sysadmin may decide he needs new hardware. Or, if he is sharp, he will recognise he can use the capacity within the existing servers. Here’s where consolidation comes into its own. You can run two (or more) totally independent, and even conflicting, virtualised computers on the one set of hardware. In our example, both computers might be running web-enabled apps and they still won’t interfere. They will be much more energy efficient, however, than two individual computers would have been.

Some organisations have found they can dramatically slash the number of servers in their organisation by consolidating them as virtual servers. This can deliver an enormous cost savings and will absolutely decrease energy usage and thus harmful emissions. Virtualisation gives value for money and is environmentally friendly.

Not only this, but virtualisation slashes the dependency between an operating system and the underlying computer hardware. Typically, when setting up a server there is a lot of work that must be performed in configuring the computer itself. The computer’s setup is largely tied in to that machine. If you wish to upgrade to a more powerful computer you generally cannot simply backup the computer and then restore onto the new machine. Instead, you must go through the format and installation and setup process from the beginning. Not so with virtualisation; once again, the file system is merely a file on disk, and the virtual computer is shielded from the real hardware, by working through an abstraction layer provided by the software implementing your virtual environments. You can now totally replace your hardware with a more powerful computer that need not bare any resemblance to your previous system. The virtualised systems won’t care; copy their disk files over and set them off and running once more. Unless something is really amiss they’ll pick up right from where they left.

Let’s check out just why Linux rules the roost, and why Windows Server 2008 has been left behind.

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