A brave new virtual world?

by Mike Bromwich, Technical Director, PDMS

The IT age has brought new meaning to many existing words – but one of the most overused adjectives of recent years has to be ‘virtual’. My Compact Oxford English Dictionary provides a variety of definitions – ‘almost as described, but not completely or according to strict definition’, and ‘(computing) not physically existing as such but made by software to appear to do so’. That being said, it fails to provide any definition for the subject of this article – virtualization – or at best only a virtual definition.

Virtualization comes in a few guises, but is generally concerned with dividing a single pool of resources to allow each resulting ‘virtual’ resource to be managed and used separately. Take a simple example: instead of buying ten separate servers – you buy a single larger server and divide it up using virtualization. Each virtual server can be used for a different purpose, and can even use a different operating system (Windows on one, Linux on another for example).

Although virtualization has come to the fore in recent years, it is by no means a new concept having been first demonstrated in the 1960s. Over the decades that followed, the move towards personal computing and a ‘PC on every desk’ limited widespread visibility of the technology, which tended to be restricted to specialized applications. In the last ten years, the growth of Internet-centric applications and ever more mobile users started to push the requirements for computing horsepower back towards central data centres, and virtualization technologies have taken another significant step forwards.

As computers become more powerful they are also becoming smaller – and so the amount of power contained within a single rack of computers is increasing at an alarming rate. ‘Alarming’, because the increasing processing power requires an increasing amount of electricity, and produces an increasing amount of heat. In today’s world where environmental concerns are paramount, the pressure is on to make more effective and efficient use of these resources.

A widely-quoted statistic states that ninety percent of the world’s computers are ninety percent idle for ninety percent of the time. It is easy to see how this can be the case – when specifying computer hardware, we usually ensure that it has the power available to cover peak requirements – even if these peaks occur infrequently. All the time that the computers are sitting idle waiting for their next task, they are still using electricity and very effectively turning it to heat – which we are then using more electricity to move around and dump into the environment. The airline industry may have one of the most significant carbon footprints, but the IT industry has to be one of the most wasteful when it comes to energy consumption.

Virtualization can bring widespread environmental benefits. Imagine a typical corporation with 100 physical servers, whirring away day-in-day-out. Typically, these could be ‘virtualized’ down to, say, ten servers – each hosting ten virtual servers. Already, this change will deliver significant savings in terms of power, cooling, not to mention maintenance and management. However, today’s virtualization is smarter than this – at night and weekends, when the business is largely idle, these virtual servers can be automatically consolidated onto three physical servers – and the remaining seven powered off. This will be entirely transparent to the users. In the morning, as people roll into the office and start work, the virtualization environment notices the increased workload, powers-up additional servers as required, and distributes the load.

The other area of virtualization which has been gaining ground is desktop virtualization. Brought to the mainstream by Citrix, this technology consolidates the increasing computing power which has been piling up on our desks, and moving it onto powerful central servers. The desktop PC is replaced by a ‘thin client’ – the abilities of which are limited to displaying the desktop and connecting to the keyboard and mouse.

This strategy brings various benefits. Centralization of facilities allows for upgrades and enhancements to be rolled-out without replacing a large estate of distributed equipment. If the thin client develops a fault or needs to be upgraded, it’s a simple task of swapping the hardware while the user’s environment, programs and documents remain unaffected. Since everything is stored centrally, the user can work from anywhere there is a thin client – and access the same environment. Backups, virus protection security – all these management task become simpler.

Ubiquitous connectivity, even while mobile will take virtualization to a new level – allowing ‘your’ environment to be accessed from anywhere. Among others, Microsoft are planning their future in a virtual world – their Midori project is set to signify the end of Windows on the desktop by adopting a network-centric, virtualized model. The next challenge will be to work out how their business model will need to change when they are no longer selling Operating Systems. The entire IT industry will need to refocus to accommodate what is likely to be the most significant change the industry has seen in the last twenty years.