Virtualisation – the grouping of computing resources – is nothing new. It has been present in high-end Unix machines for many years, and a similar concept first appeared at the time of the mainframe.
What is new, says Frank Gillett, principal analyst at Forrester Research, is that organisations are now undertaking virtualisation on x86-based systems, the chip architecture that dominates the computer and server markets.
The excitement has centred mainly on virtual machines – such as the technology produced by VMware – and their ability to increase the use of system resources.
Clive Longbottom, service director at researcher Quocirca, says most organisations use only about 10 per cent of server capacity at any one time. ‘This is because the machine has to be big enough to service peaks in demand, even though they might only occur twice a year,’ he says.
‘But virtualising resources increases use to about 60 or 70 per cent, which means that companies can save a lot of money on buying new hardware for pure capability reasons.’
Such system use, together with the fact that the technology enables organisations to run different operating systems and applications in partitions on the same physical server, means virtualisation has been targeted as a way to cut costs by reducing server sprawl. Further savings can be made in data centre space and from reduced bills for power and cooling.
Companies have also been waking up to server virtualisation technology’s ability to enhance flexibility through provisioning. Applications can be processed wherever there is spare capacity, and if one system fails, workloads can be moved away from the problem site.
But the concept of server virtualisation is much broader than any individual technology, however well marketed.
Neil Macehiter, a partner at MWD Advisors, says there is a lot of confusion as to what virtualisation means. ‘Although it has become synonymous with a certain type of technology, it is really more of an approach,’ he says.
The aim is to reduce complexity, by providing a single logical view of disparate physical resources to ease management. Virtualisation can be applied to anything, from networks to storage, and from operating systems to applications.
In the case of networks, virtual local area networks are already relatively common and enable creation of sub-nets that can be used by different classes of user for different purposes, while ensuring that they are managed and secured centrally.
In the storage world, virtualisation software has been available from large vendors such as EMC and IBM for some time, although take-up is still only at an early stage. Applications can be used to manage distributed storage resources from a central point, and to move data between multi-vendor disk arrays easily.
Interest is also growing in the virtualisation of the applications that sit on top of infrastructure. Macehiter says the growing trend towards application virtualisation is being caused by the more complex nature of software.
‘Organisations are increasingly wanting to move away from stovepipe methods of application delivery to delivering functionality across business processes,’ he says.
This is where concepts such as service-oriented architecture (SOA) come in. Taking an SOA approach involves integrating distributed applications or components to support a given business process or service. Applications and components then create a pool of shared data and functionality, which can be accessed by users as and when needed.
‘If you have several order processing applications but want to use a common engine to check customer credit balances, you have to understand what code the engine is implemented in and how you call it based on that,’ says Macehiter. ‘But with SOA you put an interface on top, using technology such as web services, to abstract the implementation away so that such issues don’t matter anymore.’
Using advanced integration technology makes it simpler to consolidate multiple instances of the same application – in this case a credit checking engine – to cut down on redundancy. It also means that if data is updated in one application, it is also updated simultaneously across other tools, increasing information accuracy and integrity.
Another nascent virtualisation software market relates specifically to desktop applications. Significant suppliers here include Citrix, Altiris and Softricity, which was purchased by Microsoft in May this year.
Forrester’s Gillett believes that virtualisation will become the standard way for dealing with IT resources. ‘In the long run, I think most technology will be virtualised. Virtualisation is part of a larger trend that some call utility computing, but which we call organic IT,’ he says.
‘It is about virtualising and automating IT to increase efficiency radically and to ensure that resources aren’t idle. It is also about enhancing flexibility, by being able to move resources around quickly in line with business needs.’
But Gillett says the key tipping points for such transformation are server virtualisation and SOA. ‘They are the two catalysts that are causing IT to realise that something profoundly different is happening and that they need to plan for it, although most companies are not doing that at the moment,’ he says.
Macehiter agrees, but believes that during the next three to five years, virtualisation technology will become ‘more baked into IT environments as a general approach to dealing with data centre complexity and how IT directors think about their resources’.
This will occur as huge vendors, such as Intel and Microsoft, progressively and routinely add virtualisation concepts into their technology. Over the past year, for example, virtualisation at the silicon level has moved out of the realm of expensive Risc processors and into Intel’s less costly x86 desktop and server chips.
Microsoft will make virtualisation technology more attractive to the mid-market when it ships Windows Server Virtualisation as a free add-on to the Longhorn Server operating system, which is due to appear at the end of 2007.
As a result, organisations will no longer need to pay for existing Microsoft Virtual PC or Virtual Server products and will be able to easily add memory, processors and other system resources.
Macehiter says virtualisation has historically been about responding to the complexity of the past to try to overcome limitations. ‘But there will be a gradual shift until it becomes the default way for organisations to think about how they deliver IT,’ he says.
‘Virtualisation will become the basis of the next-generation data centre.’
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