One of the technology industry's many dirty little secrets is the fact that computers spend a lot of their time doing almost nothing. To understand why, consider a business process you only run every couple of weeks, like processing a payroll. Because it is so sensitive and simply has to happen on a few days of the month, businesses tend to acquire a large, powerful computer that can process a payroll without ever really being taxed to the point at which the process will be disrupted.
Many businesses buy such powerful computers in case they expand and need to process an even larger payroll. It is prudent because it pre-empts the need to rebuild the payroll application.
The result of this sensible over-investment is a robust IT infrastructure that does its job well for the few days a month it is required to perform near its peak. For the rest of the working month, however, it uses only a fraction of its power.
Most companies have several such computers, each for discrete but critical business processes. Yet while these computers sit idle, the cost of operating them does not fall. An underutilised computer uses the same amount of electricity as a busy computer; occupies the same amount of space and requires the same amount of maintenance.
With the price of electricity, IT workers and floor space going up, businesses now wonder how they can put their underused computing resources to work or reduce the number of computers.
The computer industry's answer is called "virtualisation". It aims to replace the idea that a computer is a physical entity with the notion that computers can be logical constructs.
This is an important shift in thinking because today computers are seen as a resource dedicated to a single application. That thinking has led to the over-investment in largely idle computers. Virtusalisation suggests that a business's computers be considered as a pool of available computing resources that can be tapped into as needed.
Virtualisation lets IT administrators assemble computing resources into "virtual" computers that draw power from several physical computers, yet operate as a single machine.
Instead of buying a large, powerful computer to run the payroll for a few days a month, businesses can use virtualisation to assemble a logical computer that uses processing power from one server, memory from another and disk space from a third - a process that can be accomplished in a few minutes. Once the payroll is complete, the resources that comprise the logical payroll server are released back to other duties.
Michael Warrilow, an IT industry analyst and managing director with Hydrasight, says virtualisation delivers four benefits: Lower total capital expenditure, reduced operational expenditure, potential for improved operational efficiency and possible improved reliability for IT infrastructure.
Those predictions are proving true for one virtualisation user: Sydney's ANZ Stadium. IT manager David Fletcher says virtualisation allows it to create virtual servers to tackle unusual workloads, such as the demands placed on its technology when large events mean all of its 380 point-of-sale terminals are pressed into action.
"Depending on the size of an event, there can be a big load on the POS system," Fletcher says.
The stadium's strategy of leasing its servers means that buying new servers is seldom possible, while the short time between events - the stadium can be used on consecutive days - makes major IT refreshes impossible. But when its applications are not required at full throttle during events, virtualisation is the answer.
"If performance is not right, it is just a case of allocating a bit more memory to the virtual machine," Fletcher says. It is a far easier task than rebuilding a server.
Fletcher likes the flexibility in virtualisation: "We are now using wireless hand-held cash registers so people can wander around selling things."
It is a technology that relies on a database the stadium did not have. Virtualisation meant that instead of having to buy a new machine for the new database, Fletcher's service provider created a virtual server which "we had inside a day".
That kind of response has made virtualisation a hot technology. Market leader VMware's share price has recently taken a pummelling on soft sales numbers, but the ultimate endorsement of the technology came with Microsoft's inclusion of virtualisation in its new Windows Server 2008 operating system.
To be released in the second half of this year, Microsoft's virtualisation technology will almost certainly make the technique a technology mainstay.
* Most businesses have computers for discrete processes, but their excess capacities can be put to work in off-peak periods.
* Properly managed, harnessing different aspects of excess computing capacity will result in large-scale savings, especially in the areas of hardware, electricity and IT salaries.
* Virtualisation is set to become an industry standard. Major software vendors are incorporating the new technology in their latest operating systems.
Fairfax Business Media
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