Introduction to Virtual Machines

What is a Virtual Machine?

Have you ever tried using Virtual Machines? In case you’re not sure what they are, here it is. In a nutshell, a Virtual Machine is like an imaginary machine running concurrently with your local machine. By using this technology, you can run multiple and different kinds of Operating Systems in you host machine. There are actually a lot of open-source Virtual Machines out there, so you can try one of them if you have time. One of those popular VM’s are:

• Oracle’s VirtualBox: It can run Windows OS, Linux Distributions, Mac OS and others. I tried this and it’s pretty good and easy to use. It’s a free software but I’m afraid that someday it won’t be free anymore because Oracle might turn it into a commercial product.
• QEmu: It can run different kinds of Linux Distributions. I also tried this. The interface is easy to use and sometimes pretty fast too when installing some guest operating systems.
• Microsoft Virtual PC: It’s originally developed by Connectix. It runs only in Windows 7 but it has XP backward compatibility. Well, obviously, this virtual machines kind of runs Windows OS’s only. 

Why use a Virtual Machine?

• Each guest operating system you install are completely different and isolated from your host operating system. So you don’t really need to be worried if the guest OS might mess up with the host OS.
• Machines can be moved to other directories or locations, copied to one place to another and other processes that you can do just like to an ordinary file.
• It can be used to test new operating systems since Virtual Machines can be easily installed and at the same time configured.
• Each operating systems run differently. Because of this “Shared hosting” emerged. Shared Hosting is like one server host several number of websites. Virtual Machines are sometimes used in this. You run different operating systems that handles those websites. All you need to have is a one big good server.

Problems you might encounter:

• Your host operating system’s performance might decrease. When you run a Virtual Machine, it also takes up some RAM. So beware of this, it’s not proper to give more portion of RAM to your guest OS than to your host OS.
• If you used a not-so-powerful machine to run your guest and host OS. You might end up with hardware failure. So you also have to be careful when configuring your VM.