We still get asked this question frequently. In simple terms, virtualisation is taking your existing physical computers and making a ‘software’ copy of them. This is quite easy, because all the configured, important parts of your servers are already software anyway – the operating system itself, the programs you run, and the data you’re storing. Virtualisation platforms have a standard (identical) software version of the computer ‘hardware’ for all the virtual computers to run on top of – think of it like every computer in the world having identical hardware components. The operating system, programs and data run inside this ‘virtual computer’, all contained within their own little bubble – they can’t see or interact with any of the other virtual computers running on the host machine unless you network them together.
Why would we do this? Once you virtualise a computer, there are many benefits:
1) Reliability – a virtual computer (known as a Virtual Machine or VM) doesn’t depend on the physical hardware of the host computer (the physical computer) it’s running on anymore. That means you can take a VM that’s running on one (host) computer, and move it to literally any other host computer. So if I have a VM of a Microsoft Domain Controller running on a server and a critical hardware component like the motherboard in that server fails, I can take the VM of my Domain Controller and move it to any other host (physical computer). That could be another server (if I have other physical servers in my office) or an emergency repurposed PC, or even a laptop. We can recover our virtualised environments extremely quickly, far faster than repairing the physical hardware in a server (and possibly having to repair or reinstall the operating system). With the right licensing, we can even have backup copies of VMs running on other hosts that switch on automatically if the original VM stops running for some reason (called replication).
2) Efficiency – once I virtualise my computers, I no longer need a number of physical servers to operate separate tasks like Domain Control, File Servers, Exchange (email), Accounting, Virtual Desktop Infrastructure (VDI) etc. – instead of separate machines, I can run all those VMs on the one physical host. I might be able to run them all on an existing server, or I might purchase a single high-performance server that will improve performance for all those server roles. That’s a more efficient use of my budget, both initial or capital expenditure (CAPEX), and ongoing operating costs (OPEX) for electricity and maintenance.
3) Rapid Deployment – in a virtualised environment, it takes just minutes to roll out a new virtual server for a new role – there’s no procurement of expensive physical hardware, just purchase any licenses, define the VM and install the OS and you’re ready to go. Or if you have good planning and administration in place, you might already have VM templates ready to go, in which case it’s just purchase the license, start the VM and configure it. If IT need to test things, they can do the same thing with virtual PCs, having them ready to start testing in minutes or seconds without having to move an inch from their workstation.
There are many other benefits to Virtualisation such as business continuity and disaster recovery, simplified management, the potential elimination of downtime etc. but as an introduction, in just a few short paragraphs you can already see there are tremendous benefits to Virtualisation. The important point here is if you are still running servers on physical hardware, it is time to have a discussion with your IT people about why – why you’re wasting resources, why you’re exposed to exponentially greater risk than you should be, why you’re spending money hand over fist just to keep that physical infrastructure supported and operating, why it is still so expensive and slow for your organisation to add new capabilities and tools.