Around 20% of all server systems are now shipped with a virtualisation platform, an increase of more than 25% over year-ago numbers, market-watchers at IDC have calculated 

The analysts reckon 358,000 such units were shipped in the Western European countries in 2008, approximately 18.3% of all servers against 14.6% in 2007.

It forecasts that numbers will rise to almost 21% in 2010. 

We believe the current economic crisis to be increasingly intertwined with virtualisation adoption, as the combined need to squeeze costs with the existing assets and the weak demand for new hardware are accelerating its technological impact within customer installed bases, said Nathaniel Martinez, of IDC. 

The company said that it expects the number of virtual machines to exceed physical systems in 2009.

The drop in hardware spending will lead to a break point in 2009, as VM shipments will be more than 10% higher than physical server shipments, it said.

The market analysts also warn that some IT shops are in danger of being caught out by virtualisation sprawl and inadequate controls over the increasing numbers of virtualised images they deploy.