What is virtualization?
by VCP Help on 10/01/09 at 8:17 pm
Virtualization (or virtualisation for our Brit friends) is the concept of creating many fully functional computers (virtual machines or VMs) which can run simultaneously on one real computer (the “host”). Each VM believes that it is running on a normal, physical host so it runs normally without any special changes to the programming required. A rough analogy would be how you can execute many programs on a computer at once, all sharing the same CPU, memory, disk drive, etc. except we are talking about full-blown operating systems running concurrently.
For example, using VMware Workstation which is the “desktop” class product, you can be running Windows XP on your host machine. You can then create virtual machines in which you could install Linux, Windows Vista, FreeBSD and even another copy of Windows XP. Each of these machines boots, shuts-down, and behaves as though it’s a normal machine, yet it is actually running in a window on the desktop of your XP host machine. This is useful for people who want to learn about different operating systems, for example, and who don’t want to erase the primary OS on their computers. Developers also use virtualization to test their programs because if you run something inside a VM, it is partitioned-off from everything else on the computer and an errant program cannot cause harm to the host machine.
The VMware Virtual Infrastructure product line takes this concept to the highest level and allows enterprise-level virtualization for entire businesses rather than just on your desktop. One high-end server in the office datacenter can run 20 or more virtual machines, thus saving on power, space, and manpower to administer the machines. In a typical business, you may have dozens of old, physical servers taking-up space and drinking electricity. With virtualization you can take those dozens of old servers and turn them into virtual servers running on just a couple of modern, high-powered servers.
It’s a tough concept to get your head around sometimes, but virtualization is here, growing, and won’t be disappearing any time soon. That’s what makes having skills and certifications such as the VCP so valuable.
For more information, you can visit the Wikipedia page on virtualization or the VMware introduction to virtualization.
