Virtual Machine (VM) software has been around for a long time. Mac users are familiar with Parallels. On the Windows side there have been several to choose from, including one from Microsoft itself which is delivered with some versions of Windows 7, to allow users to run Windows XP programs. VirtualBox is an open source, free program available from Oracle.  It is easy to set up and fun to play with.

But wait, why would I use this?  I can think of three reasons:

1. Run an essential program on one system that doesn’t work on another system. A classic use for VM software is to run a different operating system (the guest) on your main computer (the host). Many Mac users run Parallels to be able to run Windows for an essential program that isn’t on the Mac (think QuickBooks…for small businesses, or some CAD or 3d imaging programs.)  I run Windows 7 on my iMac and laptop Macbook Pro using Parallels, but they would work fine with VirtualBox).

2. Run an older version of something that you just can’t conveniently upgrade. My own motivation for investigating this is to be able to extend the service life of a creaky mySQL database that has connections to a web site. While we’re in the process of rewriting the web site, it will still be awhile before we can ditch the old database, and in the meantime, we’re having hardware issues. So we’re hoping to use VirtualBox to migrate the old server on to a VM running on new hardware.

3. Consolidate servers. Virtual Machines can be used to provide multiple servers on a single hardware server, saving space and energy.      

4. Research, rehearsal, training and testing. Using a VM is a great way to rehearse and train for a hardware upgrade, to try out a new operating system, or to play with (virtual) hardware. Just as NASA astronauts simulate a moon landing, you can easily simulate a five-drive RAID array, and figure out how to set one up without all those pesky wires.

Next: Set up VirtualBox on Windows 7.