With server virtualisation projects currently underway inside most large companies, many are realising that there is much more to the challenge than simply consolidating server numbers and implementing a new software layer. Bottlnecks in networks and slow access to storage resources are leading to reduced performance and user frustration.

Vice president and general manager of the data centre infrastructure division of networking specialist Brocade, Ian Whiting, says companies need to take a holistic approach to their IT infrastructures to be sure that server virtualisation will actually deliver real benefits.

Whiting says many are significantly reducing the number of physical servers within their organisations, but are then striking problems when it comes to ensuring application performance remains at acceptable levels.

“You can get all the benefits of virtual machines and being able to move applications around, but then find that they cannot get access to their data,” he says. “If you’ve got 30 to 40 (virtual) servers connecting into several terabytes of storage you need very fast pipes to get the quality of service and performance needed.”

Whiting says one of the key challenges associated with virtualisation flows from the very fact that applications are no longer tied to a particular physical machine. When applications are moved between different boxes, data centre managers need to ensure that all the resources required by that application moves with it.

“If you’re running a payroll application on a server and you want to move it, you need to ensure it maintains a high degree of bandwidth, the security controls and access to storage resources,” he says. “One of the complexities is making sure the network can adapt to the application workload as things are being moved around in a virtual environment.”