Virtualisation is a technology that has – so far – proved immune to economic trends. According to industry analysts IDC, the virtualisation market was worth $1.6 billion in 2009, and is expected to grow to $2.6 billion by 2013.

And small wonder – the technology helps businesses address a raft of critical challenges. Cutting the cost of IT operations is perhaps the most significant but is by no means the only driver of virtualisation. “Businesses are increasingly looking to reduce their data centre footprint,” says Una Du Noyer, vice president and head of infrastructure and engineering at Capgemini UK. “And there are more and more worries about power. Apart from energy bills there is the carbon reduction commitment, which comes into force in April and will affect around 5,000 organisations in the UK.” IDC calculates that over half of companies now have a virtualisation project in place. In the data centre, virtualisation is being driven by the need to reduce the number of active sites, while also improving resilience and disaster recovery capabilities.

According to Lionel Lamy, a research director in IDC’s European Software and Services Group, enterprise organisations are typically consolidating four or five separate data centres to one primary site and a mirror. Virtualisation is one of the key technologies they are using to do this. But all is not necessarily well in the virtual world. Recent research carried out by Computacenter, the IT services provider, suggested that only six per cent of organisations achieved a full return on investment (ROI) from server virtualisation.

Virtualisation has certainly suffered from a degree of vendor hype, with some analysts arguing that software companies used optimistic ROI projections, based on ideal scenarios, to promote their wares. As Capgemini’s Du Noyer points out, virtualisation project ROI calculations often assume that businesses will move to new hardware as part of a server consolidation and virtualisation project. But companies would see their costs fall by moving to newer servers even without virtualisation, she says. IT departments might also have contributed to disappointing ROI and cost- saving figures, by applying virtualisation to the easiest, rather than the most important, IT workloads.

In the past, virtualisation was being used in test and development, because developers have lots of instances of operating systems and want to create new ones and take them down quickly,” says Du Noyer. “But the real return on investment is in production systems, where you have much larger numbers of servers.” And to date, even those production systems that have been virtualised have typically been the simplest. While tacking the ‘low-hanging fruit’ of file and print servers and web applications allows IT departments to familiarise themselves with virtualisation in a production environment, it will only rarely bring the same returns as projects targeting heavier-duty systems such as enterprise resource planning (ERP) or email.

“It is understandable that organisations do that, but how do you get from that point to tackling more critical systems?” asks Paul Casey, data centre platforms practice leader at Computacenter. “These are workloads that you will have to tackle at some point."

Into Production

In the past year, many organisations have got to grips with virtualising their heavy-duty production systems. “We have clients who have moved from running five per cent of their systems in virtualised environments 12 months ago to 45 per cent today,” says Jon Gasparini, principal consultant at IT integrator Morse.

This is in part due to moves by the industry to make it easier. Gasparini suggests that better support for virtualisation within IT management tools from HP, Microsoft and BMC is helping organisations bring the benefits of virtualisation to production environments. So are more specialist tools such as Quest, Platespin and Vizioncore’s vFoglight. “IT departments often hit a hard limit of 20 virtual servers on one host, because they don’t have the tools to manage greater capacities. But with the right tools you can increase that,” he says.

The virtualisation vendors have also refined their hypervisor products, so they are both more stable and more scalable. Support for more virtual processor cores and greater memory allocations have increased the range of production workloads that can be virtualised. At the same time, vendors are perhaps more realistic about the type of application loads that can be moved to a virtual machine than they have been. “We are quite specific that virtualisation is not a panacea and won’t solve all infrastructure problems,” says Neil Sanderson, Microsoft’s UK product manager for virtualisation and systems management. There is also more understanding that performance under a virtualised environment is less about capacity than how specific applications behave, he says.

Virtualisation vendors are also working more closely with software vendors, in order to ensure deeper levels of compatibility between the virtualisation environments and enterprise applications. VMware, for example, has technical teams working with ERP vendor SAP, as well as with database developers and Microsoft’s Exchange team.

“We have had to make [virtualisation management platform] vSphere more scalable than previous versions of VMware,” concedes Dave Wright, a senior director in the company’s technical services team. “Virtual machines with 256GB of memory and eight processor cores were not the type of virtual machines we originally imagined. But we’ve seen tests run on email servers with 700,000 mailboxes.” Some barriers remain, however: the consensus among experts is that there are still some applications that are not yet ready for virtualisation, and some that might never be suitable.

One area of weakness is disk input/ output (IO) capacity, and this is widely regarded as a reason IT shops have been reluctant to move databases, as well as applications such as Exchange, to virtual machines. “Database gurus don’t like virtualisation, as they like to keep databases separate,” points out Capgemini’s Una Du Noyer. “Current virtual machines are not good at disk IO so you might want to keep databases away from the virtualisation pool.”

Improved disk IO and database compatibility is very much a priority for the virtualisation vendors, however, and progress has certainly been made recently in compatibility for applications including Exchange. However, applications that make low-level calls to the operating system, which need very tight controls over latency or which require access to specialist hardware, might never make the jump.

Communications applications that make heavy use of encoding or decoding, such as videoconferencing, or which use specialist IO cards, including Microsoft’s Office Communications Server, will be difficult to integrate. So will manufacturing and industrial control systems, or measurement and monitoring systems used in labs, because of the need for the server to control interface cards.

At a more general level, however, IT departments report growing interest in virtualisation from the business. End-users have seen both performance and reliability improvements from the initial wave of virtualisation, in areas such as web applications, middleware, and file and print. They are now looking for similar improvements from more critical programs.

Businesses have also seen other, ancillary benefits, such as improved business continuity and disaster recovery. The ability to recover a virtual machine to a different physical host or server, or to move a virtual load to a different physical host for upgrades and maintenance, is already improving availability and uptime for businesses.

But the most important factor, when it comes to virtualising a production system, is planning. IT departments need to consider their server capacity, their application loads and which applications are suitable for virtualisation now, and which should wait. “The biggest issue remains what can be virtualised. Not everything is a good candidate,” says Morse’s Gasparini. “And a lot of IT teams don’t know what [servers] they have or what’s running on them.” Careful planning, as well as the right tools, is critical to successful virtualisation of production systems, he adds.

Case studies

RLAM upgrades server capacity through virtualisation

Following its decision to virtualise the majority of its servers, one financial services company has seen both a return on investment and solved its computing capacity issues