What is VMWare? This is actually a fairly complicated thing to explain, although it is obvious whats going on when you see the application running. VMware is software that runs multiple virtual computers on a single PC - at the same time - without partitioning or rebooting. On top of these virtual machines you can then run the OS of your choice. In other words you boot your machine into, say, Linux which VMware refers to as the ``host'' operating system. You then run the VMWare virtual machine, which can run a variety of other operating systems, e.g. MS Windows, as a so called ``guest'' OS. This proceedure is illustrated in Figure , while an example of the application in action is shown in Figures and .
Figure: Schematic showing how VMWare is used as a layer between the real and virtual machines.
This is not an emulator, you are not emulating the CPU or the hardware inside the virtual machine, you are just allowing another operating system to use it in parallel with the one you already have running. Each virtual machine can have its own IP number (if your machine is on a network) and you can treat it exactly as it it was another physical computer. Of course you don't really have two computers so your guest operating system ends up sharing resources with your host operating system. Basically, the more RAM you have when using VMWare the better, although I've quite comfortably used it on machines with as little as 64Mb and gotten away with it.
This is not a boot manager; boot managers and VMware are complementary. Boot managers help you select one of several available operating systems and boot it on the computer. Only one operating system is ever running at one time, and moving to another requires rebooting the system. Adding an operating system also typically requires repartitioning a disk. By contrast, VMware allows multiple operating systems to run simultaneously on the same computer. VMware can work with existing disk partitions on an IDE drive or can support new operating systems in VMware logical disks without the need to repartition a disk.
Figure: VMWare booting the virtual machine using Linux as the ``host'' OS.
Figure: VMWare running Windows 98 as a ``guest'' OS, using Linux as the ``host'' OS.
VMWare supports two host operating systems, Linux and Windows NT, and a variety of guest opertaing systems including DOS, Windows, Linux and BSD dervided operating systems. Support for OS/2 and BeOS as guest operating systems is likely to be introduced eventually.
Although it is fairly cheap for academic purchase at US$99.00 per
user licence, VMWare
The Graphics Cookbook