More than half (55 per cent) of firms deploying virtual networking infrastructure have yet to see significant operational cost or resource savings, or a return on investment, according to research.

The survey by vendor Network Instruments (NI) also revealed that 55 per cent of global organisations run mission-critical virtual email and web servers, while half run virtual DNS and DHCP servers.

"Many of the people we're speaking with have implemented virtualisation, but often lack of visibility is keeping them from realising the benefits of the technology," said Ian Cummins, NI Europe vice president.

The survey also highlighted key concerns for IT staff, with 59 per cent believing they are not experienced enough to manage the technology, while 26 per cent said lack of virtualisation-related training was affecting success.

Securing virtual networks was causing great concern to 21 per cent of respondents, while 47 per cent judged the rollout costs of the technology too high.

The survey polled 120 network engineers, IT managers and executives attending Interop 2009 last week in Las Vegas.