Organisations benefit from sticking with one virtualisation vendor, but find it hard to measure return on investment (ROI), according to a recent survey.

Virtual server sprawl, lack of visibility and reporting, and an inability to measure return on investment are hampering users, according to a double-blind survey commissioned by CA and carried out Canadian research company, The Strategic Counsel. The survey covered 808 organisations with 500 or more employees in Asia-Pacific, the US and Europe, all of whom are adopting virtualisation.

Respondents could not say whether their deployment were a success, because they could not quantify ROI.

A big majority (71%) are deploying multiple server virtualisation technologies, including operating system and hardware virtualisation, operating system partitioning, para-virtualisation, and/or clustering. And companies that carried out an inventory and consolidated their physical servers got more out of virtualisation.

But organisations using multiple virtualisation technologies are suffering, according to report author Warren Shiau. They are 75% more likely to complain about higher administrative workloads than those who stuck with one technology; 66% more likely to complain of higher configuration requirements; 50% more likely to suffer server sprawl, and 47% more likely to have reporting troubles.

Companies are deploying virtualisation to improve utilisation reliability and uptime, according to the survey, but they have no idea whether it is working because of difficulty measuring the performance of the virtualised environment.

The findings were made up from 30% of respondents from North America, 37% from Europe, and 31% from the Asia-Pacific region. Of the organisations surveyed, 67% had between 10 and 99 physical servers, and 22% had more than 200. Over 100 respondents were based in the UK.