The container concept is still new and critics see potential flaws. Some worry about security, although vendors say the boxes are hard to break into and can be housed on private lots. Others worry about the reliability of having a single power or network connection for such a dense load of equipment. There are also mundane issues, like not being able to open a container to service it in heavy rain, unless it's covered up.
Vendors are still figuring out the best way to design the products, too. Sun's Modular Data Centre, for example, has server racks along both sides of the container and a narrow aisle down the middle, and is accessed by a door at each end. HP chose to put racks on one side of the container only, with a sliding door behind them to provide access at the back as well as the front. A narrow space behind the racks allows HP to mimic the "hot aisle, cold aisle" configuration in normal data centers, to minimize the retraining required for IT staff, Cumings said.
Microsoft is a big fan: It has said it plans to install more than 200 compact data centres on the ground floor of a new facility in Chicago. It hasn't said yet which vendor will provide them.
Sun's early customers include Hansen Transmissions, a Belgian industrial manufacturer, and Mobile TeleSystems, the Russian mobile operator. The Stanford Linear Accelerator Center in California bought two and has posted a white paper and time-lapse videos showing delivery of the first.
Sign up for CIO Asia eNewsletters.