Users are paying little attention to some of the downsides of virtualisation in their haste to reap the benefits that the technology can bring.

That's according to Burton Group analyst Jack Santos who has co-written a briefing paper, The Dark Side of Virtualization for Burton clients detailing some of the problems facing virtualisation users In the future.

Santos stressed that virtualisation had many advantages for organisations - and that there were considerably more advantages than disadvantages - but said that there were still some issues that needed to be resolved, particularly regarding management and security.

In an interview with Techworld, he said that IT manager had "conveniently" ignored the risks, because they outweighed the benefits. However, he warned, this was a situation that could change. "As deployment expands [especially in a cloud-oriented world] the repercussions may get more significant," he said.

He said that management of virtual environments would remain a thorny problem particularly given the disparate number of providers and the fact that even the virtualisation software companies themselves had less than complete offerings in this space, pointing that few virtualisation tools integrate with general data centre management software such as Tivoli. He said that he expected the situation to stay fragmented for some time to come. "Mideast peace, at this stage, will be easier than getting vendors to play," he said.

The other problem area for virtualisation was security, he said. To date, he wrote in the report, there have been no public breaches of a virtualisation hypervisor - although, he noted, the Xen hypervisor had been exploited by Invisible Things Lab at Black Hat 2008.

"There is no question that hypervisor technology brings with it an expanded vulnerability to threats," he wrote. Although he pointed out that there was a paradox in this. According to Burton's Laws of virtualisation security, users increased security risk by adding complexity but reduced it by adding another means of separation.

One area that is improving however is licensing. Although Santos mentions some of the problems in his report, he said that vendors were working together to solve some of the sticking points, although he warned that it was up to users to push vendors harder. "Licensing has made tremendous strides, especially in the past year (with) most of the vendors are very open to dialogue. Customers need to continue to put on pressure when terms don't meet their needs.

The Dark Side of Virtualization is part of the Burton Group executive advisory series.