Product Reviews

Virtual Machines Improve Success

Emulate other operating systems with VMware 2.0.

VMware is a truly amazing product, based on a simple concept of the virtual machine, or VM, which is a computer emulated in software. VMware lets you open a window that appears to be a separate computer to the software inside the window. The result is that you can have a host operating system (where VMware itself runs) and a guest operating system (or multiple guest operating systems) running within VMware. Looked at another way, VMware gives you the advantage of a dual-boot computer without the necessity of rebooting to switch operating systems. You can network between the host and guest systems, or even cut and paste from one to another.

VMware doesn't take much to set up; this screenshot was taken less than half an hour after cutting the shrinkwrap.

VMware runs on Windows NT, Windows 2000, or Linux as the host operating system. For this review, I looked at the Windows version on Windows 2000. Supported guest operating systems include FreeBSD, many variants of Linux, MS-DOS 6, and Windows 3.1, 95, 98, NT, and 2000. The VM emulates (perfectly, as far as I could tell) an Intel Pentium PC with up to 512M of RAM, SVGA graphics, a SCSI adapter, access to CD-ROMs and other drives on the host machine, a virtual Ethernet card, and Sound Blaster support. You can set the networking up so that the guest OS can communicate only with the host OS, or so that it’s “bridged” and looks like a separate computer on your LAN.

Setup is simple: Insert the VMware CD, answer a few questions, and away you go. You can then install any operating system you want into the new VM by using the Configuration Wizard. It’s especially easy to use the “ready to run” operating systems that ship with VMware: SUSE Linux 6.3 or TurboLinux Workstation 6.0. Copy the appropriate disk image file to your hard drive, launch VMware, load the file, and you’re immediately running Linux in a window on your Windows computer. 

Other features include nonpersistent and undoable disks, so you can experiment without destroying a new operating system. VMware also has the capability to suspend and restore sessions without going through a shutdown and reboot sequence, and can use real disk partitions or large files to store the guest operating systems. The VMs are isolated from the host OS. In fact, you can even crash a VM without affecting any other program running on the host.

After using this program, I can’t imagine doing without it. It helped me get acquainted with operating systems that are new to me, such as Linux and FreeBSD. It’s also great for tracking down bugs reported by customers—without having to dedicate a computer to their configuration. You can use Windows 2000 on all your computers and still have the ability to debug Windows 95 or even Windows 3.1 problems in their native environments. If you’ve ever run out of computers to test software on, this is one product that you’ll definitely want to add to your toolkit.

Download a trial version of VMware from the company’s Web site, where you can also purchase the product.

About the Author

Mike Gunderloy, MCSE, MCSD, MCDBA, is a former MCP columnist and the author of numerous development books.


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