What is Virtualization?

Category: Software

Virtualization is a computer term you may hear often, if you're in the IT business. Small business and home computer users are exposed to virtualization rarely, if at all. But virtualization can come in handy for even casual computer users under certain circumstances, so here's a simplified explanation of the term...

What is Virtualization?

Virtualization and Virtual Machines

Virtualization is the simulation of a computer hardware environment by software. Virtualization software runs "between" the computer hardware and the operating system (Windows, Mac OS, Linux), accepting input from the OS and redirecting it to the appropriate hardware addresses. The virtualization software also does the reverse, catching output from hardware and redirecting it to the appropriate places in the operating system. The beautiful thing is that the operating system doesn't know or care if it's running on physical hardware, or a virtual machine that only exists in the memory space of a computer.

Virtualization enables you to run Windows on a Mac, or Linux or Mac OS on PC. It also enables application software written to run under Windows to be run on a Mac computer. The advantages of virtualization's cross-platform flexibility include the ability to do the following:

  • Run older programs under virtualized copies of compatible older operating systems; your Windows 95 game can be played on your Windows 7 computer. Virtualization used this way can save businesses the cost of upgrading applications that work perfectly well to never versions designed for the latest OS.
  • Confine applications to a "sealed" virtual machine within a computer's RAM. Confining applications to a secure "sandbox" through virtualization makes it safer to develop and debug applications without corrupting the rest of the system.
  • Host multiple Web sites on one physical server under different operating systems. Yes, one machine can have Windows, Linux, and other operating systems running in virtual machines simultaneously, so each Webmaster can have the OS environment of his or her choice. Web hosting firms use virtualization extensively, and so do some large enterprises.

A completely virtualized system of OS and applications can be stored offline in an image file on hard disk or optical media, preserving a snapshot of a "baseline" system. If you want to configure a new computer for a new employee, you just copy the image file onto the new computer and it's up and running in the company-standard configuration.

VMWare is one of the most popular virtualization software environments on the market. While it can be used on a home computer, VMWare is really aimed at enterprise systems. Windows 7 comes with virtualization built in, specifically to let users run Windows XP under Windows 7 so they can keep using applications that require XP. See my related artile on Windows 7 XP Mode for more on that. The open source Xen virtualization standard is the source of virtualization applications for servers, desktop/client machines; and cloud computing environments.

Virtualization is touted as a new innovation, but in fact nearly all applications ran in virtualized compartments on mainframe computers decades ago. When I started my career at IBM in the early 1980's, we used two mainframe operating systems: VM (Virtual Machine) and MVS (Multiple Virtual Storage). So you can see why "old-school" IT pros tend to roll their eyes at all the hubbub about virtualization. To them, it's just been rediscovered, not newly discovered.

Are you using virtualization on your PC, Mac or Linux computer? Post your comment or question below...

 
Ask Your Computer or Internet Question

  (Enter your question in the box above.)

It's Guaranteed to Make You Smarter...

AskBob Updates: Boost your Internet IQ & solve computer problems.
Get your FREE Subscription!


Email:

Check out other articles in this category:



Link to this article from your site or blog. Just copy and paste from this box:

This article was posted by on 16 Sep 2010


For Fun: Buy Bob a Snickers.

Prev Article:
Photo Printer Buying Tips

The Top Twenty
Next Article:
Online Photo Printing

Most recent comments on "What is Virtualization?"

Posted by:

jodie_microsoft_smb
16 Sep 2010

There are so many options when it comes to virtualization, so you definitely have options – take a look at MS’s virtualization solutions for servers, data, and desktops. Here’s a link with more information: http://smb.ms/alF3LV

Regards,

Jodi E. - Microsoft SMB Outreach Team


Posted by:

Josh
16 Sep 2010

I currently run Win XP inside of Ubuntu Lucid to access websites that won't load in Firefox on Ubuntu. I also use Ubuntu Lucid under Windows XP to keep from getting a virus or other malware by browsing less securely in Windows XP with firefox or Internet Explorer. I do this with the official non-opensource version of Virtualbox. I also use Wine in Ubuntu when it works but when it doesn't I use Virtualbox or boot into Windows XP. Most of the time I just run native applications in Ubuntu. I like having the choice of using Windows but I hardly ever do. My main reasons for leaving a windows partition is that wine and vbox don't usually work with copy protected windows software CDs, I like to watch movies on Netflix and Netflix streaming doesn't work with Ubuntu, and I had 2 copies of Windows XP from a long time ago before I switched to ubuntu. I don't intend to upgrade to Vista or Windows 7. I may have to get one of those Roku Netflix streaming boxes when Windows XP support is discontinued. It's probably cheaper than Windows anyways.


Posted by:

DTheis
06 Dec 2010

Informative article Bob.
Just one observation; it is still a bit too technical.
Companies as well as individuals stand to benefit a lot from Virtualization.
It is my believe that the concept of virtualization, its benefits, advantages, etc can be explained in a more down-to-earth manner, hence - http://virtualizationguide.blogspot.com

Thanks for your contribution


Posted by:

Vanessa
04 Feb 2011

I thought this was one of the easiest to understand explanations of virtualisation that I have ever read. I understood the basic concept of virtualization but did not know how to put it into simple words. Your article also gave me greater insight into how it actually works. Thanks very much Bob!


Post your Comments, Questions or Suggestions

*     *     (* = Required field)

    (Your email address will not be published)
(you may use HTML tags for style)

YES... spelling, punctuation, grammar and proper use of UPPER/lower case are important! And please limit your remarks to 3-4 paragraphs. If you want to see your comment posted, pay attention to these items.

All comments are previewed, and may be edited before posting.

NOTE: Please, post comments on this article ONLY.
If you want to ask a question click here.

Free Tech Support -- Ask Bob Rankin
RSS   Add to My Yahoo!   Feedburner Feed
Subscribe to AskBobRankin Updates: Free Newsletter
Copyright © 2005 - Bob Rankin - All Rights Reserved
Privacy Policy -- See my profile on Google.
[an error occurred while processing this directive]


Article information: AskBobRankin -- What is Virtualization? (Posted: 16 Sep 2010)
Source: http://askbobrankin.com/what_is_virtualization.html
Copyright © 2005 - Bob Rankin - All Rights Reserved