Rationalizing server estates has been one of the most significant datacenter trends of recent years, driven by the twin needs to make server management more cost effective and the growing constraints on power.

The major IT vendors have sensed the change and both IBM and HP are currently turning themselves into pioneers of the new frontier through internal projects. The approaches of the two companies may differ but their aims are identical -- to cut costs, simplify their datacenters, and create a center of excellence as a marketing tool.

The reliance of corporates on their computer networks has increased massively in recent years and so has the server count. The army of staff required to maintain these critical systems, together with new requirements such as data sharing with business partners and mobile working for employees, is driving costs and complexity through the roof. Current research by market analyst Quocirca, in a report called Datacenter Asset Planning, highlights the problem.

The report, taken from a survey of over 300 senior IT managers, shows that 28 per cent do not know the exact number of servers they have, 22 per cent say it could take up to a day to find a server that has gone down, and another 20 per cent say it would take longer than that.

With office space at a premium, the need to consolidate as much of the server population is obvious.

"Space and power constraints are beginning to hit datacenters," Dennis Szubert, who wrote the Quocirca report with Clive Longbottom, says. "Eleven per cent will run out of space this year, while 14 per cent have already hit a power supply limit."

It is therefore hardly a surprise that consolidation, and more particularly, virtualization, are in the spotlight. "Companies have been trying to consolidate servers for years," Szubert explains. "but, until virtualization appeared on industry-standard servers with VMware, you were restricted to using homogenous workloads on a single physical server. VMware changed all that because each virtual server gets its own copy of the operating system and is isolated from the other virtual machines running on the same hardware. Now, it's probably better to consolidate different workloads onto the same physical server so that you don't have simultaneous usage peaks."

It is against this backdrop -- familiar to some of the more go-ahead IT departments -- that IBM and HP are taking center stage.

IBM plans to reduce its server headcount from over 16,000 servers of various types to just over 100 System z9 and z10 mainframes running Linux. The initiative also forms part of the company's Project Big Green which aims to reduce the computer giant's environmental impact. The project is broken down into four tranches and the first stage is in progress to reduce 4,000 servers to 30 mainframes.