In recent years, virtualisation has become a central plank of many data centre strategies. But, according to analysts at IT advisory group, Gartner, its broad application within the enterprise has only just begun. It estimates that by the end of 2006, 540,000 virtual machines had been deployed across the globe; by 2009, that number will have risen to more than 4 million.

At multiple levels – servers, storage, PCs, networks, operating systems, applications – virtualisation is offering hard-pressed IT management the opportunity to build scalable and cost-effective IT infrastructures that are capable of serving the enterprise demands much more responsively. But while there has been massive interest in virtualisation, the enthusiasm for the different application areas of virtualisation varies widely.

Server virtualisation – in particular on x86-based boxes – has been the vanguard of the virtual revolution. According to market watcher IDC, in 2005, 5% of new servers being installed in businesses were being used in a virtualised environment; by 2010, it predicts, that number will be 15%. And while those early adopters were implementing server virtualisation for consolidation, new uses in areas such as business continuity, are driving up adoption rates.

At the operating system level, growth rates look even more stellar. Analyst group Gartner reports that the 5% of OSs that are currently deployed in virtual environments will have grown to 40% by 2009.

“The number one draw to virtualisation is cost reduction,” says Thomas Bittman, an analyst with Gartner. “Mostly it’s server equipment, because this is a great way to consolidate hardware. So that’s where businesses start, and that’s the loudest buzz right now.” Once IT executives appreciate the benefits in this area, they can soon become virtual evangelists, spotting opportunities across the enterprise infrastructure, he adds.

One such area is storage virtualisation, where the technology can be used to both create a pool of storage resources shared by multiple servers, as well as mitigating some of the difficulties associated with managing heterogeneous storage networks. “Storage virtualisation has come of age,” enthuses Laura DuBois, an analyst with IDC. According to a recent IDC study, 49% of large enterprises have already deployed some storage virtualisation technology.

Elsewhere companies are looking at virtualisation to reduce the overhead associated with managing their PC estates. By providing virtual PC images on servers, organisations can reduce their desktop hardware and maintenance costs while creating standardised environments and easing deployment.

A survey in 2006 by Enterprise Management Associates found that desktop virtualisation was already deployed by 5% of large enterprises (with an average of 9,000 desktops). And over the next few years, that penetration is expected to grow rapidly, says the research group. Nevertheless, some industry watchers sound a note of caution. A recent survey by IT management software vendor CA – distinct from this Research Report – found that nearly a third of those organisations that have already deployed server virtualisation have either not realised the return on investment – or have not measured it.

And buyers should beware of exaggerated savings projections from vendors, says Matt Brudzynski, senior research analyst at Info-Tech Research Group. “In their pitches to customers, vendors tend to exaggerate the number of servers that can actually be consolidated, which can be misleading,” he says. “Vendors are quoting high consolidation ratios of 12 or more virtual machines per processor, while in reality only about half that is the common average at this time.”

As adoption rates suggest, though, those numbers are alluring enough for most IT organisations.

Further reading

• Virtual virtues
  The new generation of virtualisation technology presents a compelling proposition.
  

• Virtual reality
  Users report impressive benefits from introducing virtualisation. But this has given rise to some unrealistic expectations.