Sometimes we don't really see what our eyes are viewing. That's true with your computer screen, and it's true in nature as well. Oh sure, we can say what we think we're seeing, but we're missing the big story such as the man behind the curtain, to recall a famous phrase from an even more beloved movie.
A few days ago, however, I stood on the front deck of my house and watched a line of angry gray clouds sprint across the sky heading northeast. There was literally a line of demarcation in the sky: on one side was the remainder of a blue sky, running as fast as it could to flee from the dark thunderstorm chasing it along. As I watched the storm approach, I thought about one of the most fascinating bits of weather trivia I ever heard: the weight of rain clouds in terms of elephants [ABC has unfortunately removed the 2003 news article - Ed.].
Every cloud is made up of moisture, of course. On a day like today, a single fluffy cloud contains about 550 tons of water. Your average elephant weighs about six tons, so that means that those happy spring clouds are equivalent to around 100 elephants.
A bigger storm cloud, more like the one I saw barreling into the area recently, is more like 200,000 elephants in terms of weight. That's quite a jump, and it's kind of humbling, funny, and awesome to think of 200,000 elephants stampeding across the sky.
No such emotions attach to the numbers associated with a hurricane, however. Instead of awe or humor, now we're talking absolute terror. Instead of 100 elephants, or even 200,000 elephants, the water in a hurricane is equivalent to 40,000,000 - yes, forty million - elephants. Forty million elephants in the sky, bringing destruction and fear. Forty million elephants.
Next time you look at a cloud, think about how many elephants are in it. You had no idea that a cloud was so massive, and no idea that a creature so huge and seemingly earth-bound can be used to understand something so apparently light and ephemeral, did you?
And that brings us to virtualization software. You don't necessarily see what's really there.
Virtualization software allows you to run multiple operating systems on one machine at the same time. Yes, that's a gross simplification, but let's keep things simple. If you're really interested, Wikipedia gives a good overview of virtualization that will help clear things up, or read the explanation offered by VMWare, one of the leading companies in this area.
I've been working with virtualization software for quite some time, and sometime watching and waiting until it became more widely usable. In the last few years there's been a tremendous growth in the virtualization options that computer users have available to them. Security people in particular tend to be very familiar with the technology.
VMWare. As far as I'm concerned, the king of the mountain was, and still remains, VMWare. You can pay for various versions of VMWare's software, and in my opinion they're worth it. In the last few months, however, VMWare has reduced the price for both its Player and now its Server to zero. Want to use VMWare on your Windows or Linux box to run other operating systems? Thanks to VMWare's actions, you have no excuse. And now it appears that VMWare has gotten its flagship software running on the new Intel-based Macs in the lab, and will hopefully be releasing the software sometime soon. Once that happens, an Apple Mac becomes the only machine able to legally run Mac OS X, Windows, and Linux at the same time, thus causing me to drool in anticipation.
Win4Lin. Win4Lin is for Linux users who want to run Windows on their boxes. Years ago I used to rely on Win4Lin to run Windows 98 inside Red Hat, Libranet, and K/Ubuntu, and it worked well. For Penguinistas who need Windows, Win4Lin might be the perfect option (although I've heard that Win4Lin Pro, which supports installing Windows 2000 and XP, isn't quite as robust as Win4Lin Classic, which only supports the Windows 9x line).
Xen. The object of a lot of attention, the open source and free Xen will undoubtedly show its face on more and more Linux distros as it matures. Since it's part of the kernel, performance is lightning fast.
Parallels. While Mac OS users are waiting for VMWare, they can try out Parallels Workstation, which is here and working now. Although the software has worked on Windows and Linux boxes for some time, it is the new support for Mactel hosts that has drawn a lot of attention in the last several weeks. Friends of mine are using it on their new MacBooks, and they report awesome speed, stability, and success.
Microsoft Virtual PC and Virtual Server. Microsoft purchased Virtual PC from Connectix since it was the leading tool at the time for Mac users to run Windows. Unfortunately, it always ran Windows slowly (since it was emulation, not virtualization, software); even worse, it doesn't work at all with the new Intel-powered Macs, and it's not clear if Microsoft is going to port the software or not. Virtual Server, however, is a different story. Also purchased from Connectix, Microsoft is making a big push with Virtual Server by recently announcing that it is now free. Even bigger, Microsoft will also support Linux installs under Virtual Server. Is that the sound of chattering teeth in Hades I hear?