Despite the well documented benefits of server virtualisation, IT managers need to be aware of a number of pitfalls if the virtualisation experience of the University of New South Wales (UNSW) is anything to go by.
Speaking at a recent Dell virtualisation roundtable in Sydney, Charles Nolan, an IT consultant at UNSW, said that while the server virtualisation component of the university’s shared services program, which began in 2007, had brought many benefits, it had also presented a new set of challenges.
During the initial stages of the project it quickly became apparent that a simple one physical server to one virtualised server approach of about 100 physical servers resulted in the same headaches that were plaguing the university, Nolan said.
“We had rubbish running on the old physical servers, we virtualised that rubbish and then had virtual rubbish running on our virtual server farm,” he said. “One of the things we learnt was the physical to virtual process is good for a while but after a time you have to stop it as you’ll just go blind in the long term.”
Where possible, UNSW now builds a new implementation on top of each new virtual server, avoiding the complexity of redundant data and applications, Nolan said.
“Virtualisation in itself only solves a physical space and utilisation problem it’s not the answer to the whole piece,” he said.
Nolan said another key learner from UNSW’s virtualisation experience was that its existing server-based back end infrastructure support model was not able to scale to deal with the proliferation in virtual servers.
“The growth caused by virtualisation -- in people, 30 per cent growth in our server environment, and up to 60 per cent growth in our storage environment -- meant we were using small IT shops systems and infrastructure to run what was becoming a big IT shop,” Nolan said.
In the two and a half years since starting the project UNSW has grown to over 1200 servers of which 700 are virtual running across Unix, Wintel and Linux environments.
“We’re running into virtual problems now – the growth in server numbers and their management and the decommissioning of the old servers,” he said. “Virtualisation has it own problems around physical configuration as well – it isn’t all there up in the cloud if you are running your own virtual storage and server environments. You have to really understand the physical topology as well as the virtual one.”