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Virtual Machines: A Logical Evolution of Operating Systems : Page 2

The same properties that made virtual machines (VMs) on IBM mainframes indispensable in the 1960's will eventually make VMs indispensable on today's servers and desktop machines. But as of today, they still have some evolving to do.


Do You Even Need a Full OS?

As a modern computer owner, you own a powerful machine capable of millions of operations per second—more power on your desktop than the 1960's era IBM mainframes. Therefore, your machine is theoretically capable of running any modern operating system. But because many commercial OS producers still collaborate closely with hardware vendors to produce combinations that run only on specific machines, and because modern OS's are still made so that they expect to be "close to the metal," you can't buy a bare-bones, bootable hypervisor VM. Instead, I'm afraid you're stuck with loading a full copy of some OS, a VM, and then running guest OS's on top of that.

The question is, why is this still true? Why isn't there a minimal hypervisor OS available? Perhaps you need to ask the major OS companies' marketing departments. As a computer owner, do you really want to have a full-blown, close-to-the-metal OS that you'll have to rebuild whenever there's a problem? The first company to make a successful bootable and efficient hypervisor for PCs will make a fortune.

The first company to make a successful bootable and efficient hypervisor for PCs will make a fortune.

The last time you installed an operating system from scratch (not from a stored image) or bought a new computer, how long did it take you to get that machine set up exactly the way you want? New machines usually arrive with OS installed, but without any of the programs you use or the settings you prefer. Perhaps you're more organized than I am, but it usually takes me several weeks to get a machine into the exact configuration I like. Sure, I can get it into the ninety percent range fairly quickly—a couple of evenings of installing, uninstalling, and reinstalling software, changing settings, copying files from my old machine or backup CDs, but for those first few weeks I constantly find little niggling things missing: A Word macro from a template I forgot to copy, file manager settings, missing email or address archives, connection settings, utilities I've written or downloaded, etc. I find I need to keep my old machine around and running for a while just to ensure that I have access to all the clutter of files and applications that make my computer my computer.

Wouldn't it be easier if you could simply copy a file and run your old setup on your new computer directly, knowing that all your settings accompanied the file? You could, if you didn't have to muck about with a new OS copy each time; in other words, you could if you were running a virtual machine.

Why Can't an OS Behave More Like a File?

As you'll see in the in-depth articles in this special report, VMs simplify OS's by reducing them to single files that you can copy, backup, clone, deploy quickly and easily, and to which you can accept or deny changes. VMs have already become indispensable for consolidating servers to take full advantage of their power and resources, testing, maintaining large banks of unique machines, and duplicating an environment to ferret out problems. They're rapidly making inroads onto developer's desktops as well, because they let you keep your tried-and-true production setup intact while testing new software and beta releases safely, or running multiple OS's for development purposes—all without the hassle and expense of maintaining and changing hardware, or dealing with multiple reboots. Managing change is an increasingly onerous task, but managing files is a well-known and well-understood process.

Today, we're only part-way there—but far enough along that you should seriously consider running on a VM all the time. Microsoft has been passing out VirtualPC images to early testers for some time, and they're so convenient that it's hard to imagine going back to a time when you would have to set up a full system simply to test drive some new software. To see the full effect, you'd need to be able to get and install full VM images, already set up with the software you need instead of building your VM from scratch, the way you currently install an OS on your machine. That's not possible with for-profit OS versions (yet), but you can already download pre-configured images from VMWare's Virtual Machine Center—if you're satisfied with running Linux VMs. In the future, people will feel the same way about all OSs: Can you imagine having to reinstall an OS from scratch? How quaint!

A. Russell Jones is the Executive Editor of DevX.
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