Why

I have been interested in virtualization since I first downloaded VMware Workstation back in 2002. Back then we were running VMware on machines with 256MB of RAM and a Pentium II 266MHz processor. It was cool to run both Linux and Windows simultaneously – and it solved a number of problems with Linux not being as usable as it is now. It also opened up a new world: I could play around with different operating systems as Windows 95, 98, NT4, 2000, Sun Solaris, BeOS and so on without having to reinstall my computer.

Virtualization is not a new technology. The old mainframes have done this for quite some time. But, as you might know, mainframes are not the cheapest computers around, and they do not get retired as fast as regular computers. So, mainframe computers are systems only accessible for a lucky few administrators. And, I guess that they do not play around with them as we do with our computers.

Nowadays, the industry have discovered that you can do the same with low cost, off the shelf hardware as you can do with mainframes. Simultaneously, people have discovered that laptops are convenient. As the mainframes are leaving the server rooms, the desktops are leaving the offices. The server industry is becoming far more off-the-shelf-oriented while the users are becoming more and more mobile.

Computing power is no longer calculated as a function of how many processors and how much memory you can fit in a single cabinet. Nowadays, the power is calculated as a function of how many servers you can place in a single data center. Clustering and distributed computing are hot technologies if you need a huge amount of computing power. But, there are other useful areas of servers too: A large number of companies have large pools of servers which does nearly nothing. They might have print servers, file servers, mail servers and so on. Each and every one of them important, but they do not use their resources efficient.

Back in 2001 we spent time playing with Pentium II processors and 256MB RAM. Today we are playing around with quad core 2,66GHz processors and 4Gig of RAM. And that is just our desktop machine. Our servers are even more powerful. As quite a few have discovered, all this extra computer power is not always needed to do simple tasks. Having a quad core to print documents are a waste of resources while maintaining the hardware costs money – both in pure administration and in power & cooling.

As the computing power in each server have exploded, the old idea of partitioning the server to run multiple “machines” on one physical machine have reappeared. Instead of five physical machines you can have one running five operating systems at the same time doing exactly the same as the five machines you replaced did. The power bill is drastically reduced while administrating the server is easier than ever.

This is the area I will be exploring in this blog. I will try out different virtualization software such as VMware ESX, VMware Server and Xen. The main reason for doing this is that I am curious – but the knowledge gained from this project was useful for my master’s project too. The project was about the possibility to virtualize computer labs as most students today have laptops.  The final report is available here.

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