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