Tesco has jumped on the virtualisation bandwagon by using the technology to handle its real-time sales systems. The supermarket giant has turned to Citrix and HP to cope with its 1,500 sales messages every second.

Britain's largest retailer had been looking to virtualisation to reduce the reliance on physical servers in an attempt to both cut capacity and reduce carbon emission. By installing the virtual servers, Tesco hopes to be a step closer to hitting its target of a 20 percent reduction in carbon emissions.

The company will be running its RTS system using Citrix XenServer running on HP ProLiant BL680c G5 blade servers. Following the virtulisation of RTS, Tesco is now looking to virtualise 1,500 physical servers on XenServer, including 80 Citrix XenApp servers with the aim of a 10:1 consolidation ratio for physical to virtual servers. This is turn should lead to greater server efficiencies with a target of 70 per cent CPU utilisation on the servers, as opposed to the current six per cent.

Tesco has also been able to use the XenMotion live migration feature of XenServer to migrate virtual machines to other physical hardware, with zero downtime, allowing patches and updates without disrupting users, enabling the supermarket company to to remove its clustering back-up technologies and replace them with virtual servers.

Nick Folkes, IT director at Tesco, said: "After conducting a major evaluation of virtualisation providers, we went with Citrix based on the strength of the Xen technology, the ability XenServer has to provide high levels of performance for heavy duty 64-bit applications, its licensing model and its UK-based engineering team - decisions that have already paid off for us.

"The virtualised RTS environment uses less than half of the energy of the physical bare metal equivalents, which supports our CO<sub>2</sub> targets and means we have already saved a significant amount on our electricity bills. We're running far more efficiently and the ongoing management of the environment is much simpler."