What Is Virtualization

What is Virtualization?
Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a storage device or network resources. For example you can run a virtual Windows operating system within an actual Linux system, thereby giving you two working systems on one set of hardware. This type of approach allows you to centralise the management of your network.
So what are the Advantages?

• Less hardware is required to run the same amount of software, therefore saving in hardware costs. You could happily run all your applications on one server while running four virtual servers inside it performing other roles.


• Data recovery is simplified. If your virtual server becomes corrupted then you just delete it and restore from a virtual backup. There is no need to restore the system from scratch and then restore from a backup. This allows the system to be recovered in a matter of minutes.


• Virtualization allows you to test different software configurations on different platforms before you deploy it. This allows you to tinker to your hearts content with configurations without the possibility of damaging the existing network.


• Reduces energy consumption. You are running less computer hardware to do the same amount of work.


• Improved system reliability and security. Virtualization of systems helps prevent crashes due to memory corruption caused by software like device drivers.

So what are the Disadvantages?

• You can get magnified physical failures. For instance if your main hard drive (or raid configuration) containing all your physical and virtual data goes down you would have to restore all your servers (physical and virtual).


• Virtualization requires more memory and processing power. This would need to be factored into any virtualization strategy.


• Training. Network administrators might not have the skills necessary to administer a virtual environment and would have to be trained.


• Complex troubleshooting when things don't work. Is there a issue with the virtual machine or some other problem?

Virtual Software choices
There is a multitude of companies offering their own flavour of virtual software ranging from the simple to the complex. The main competers are detailed below:
VMWare
Oracle Virtualbox (I use this software for my own systems)
Microsoft Hyper V
Citrix Xen Software
Overview
Virtualization is here and it is here to stay. It makes administering a network easier by centralising the management while reducing energy and hardware costs. Yes it also has its drawbacks but these are far outweighed by the positives.