Microservers: Small Footprint, Powerful Punch Page 2
Microservers vs. Server Blades
The difference between microservers and server blades is very similar to the difference between a netbook and a full-fledged laptop: A netbook is compact, consumes little power and is suitable for a limited range of light duties, while a laptop is bigger and more power hungry but can generally handle anything that is thrown at it.
Translate this into the server world, and you get blade servers, which can run any application you want -- but require substantial amounts of power and cooling, and take up a considerable amount of rack space. You can pack many more microservers into the same space, and these microservers consume less power and heat. If you need servers only for light duties such as web serving -- perhaps in a server farm where customers want their own single-tenancy server -- then microservers are ideal; a full-fledged blade would be overkill.
Of course, another alternative would be to run multiple virtual machines on a single physical server. However, it's interesting to note that Facebook is considering using microservers as an alternative to running virtual machines. That's because, according to Facebook Labs' Gio Coglitore, virtualization makes it hard to scale and because it makes the physical servers supporting multiple virtual machines more important than he would like. Microservers are inexpensive to replace, and they have a limited impact when they fail, he said.
There's another reason microservers are beginning to represent a real alternative to virtualization, and that comes down to the falling cost of microservers, Tom Nolle, principal analyst at CIMI Corporation said. "The idea of virtualization is to take a server and make it into several virtual machines because the server has more capacity than is needed for one application. But as microservers get cheaper, it makes it possible to dedicate a server to a single application again instead of sharing the server. Remember that there is a cost to virtualization, both financial and in terms of performance." Using virtualization also leads to the risk of vendor lock-in.
It is still very early days for the microserver market, and it remains to be seen whether early entrants like SeaMicro and Dell will face increased competition from established server vendors like HP and IBM. Intel for one expects to see considerable growth in the market, but forecasts in aggregate estimate that microservers will end up making up less than 10 percent of the server market for the next four to five years. SeaMicro's Feldman believes the microserver market will be worth $8 billion to $10 billion by 2015.
Paul Rubens is a journalist based in Marlow on Thames, England. He has been programming, tinkering and generally sitting in front of computer screens since his first encounter with a DEC PDP-11 in 1979.