Hewlett-Packard became the latest vendor to announce a "mini-data center" housed in a shipping container, which can provide a way for companies to add compute capacity when power and cooling systems in their existing data centers are maxed out.

HP's Performance Optimized Data Center, or POD, will be available in the U.S. by the end of the third quarter and worldwide a few months after that, the company said Wednesday. HP joins Sun Microsystems, Rackable Systems and IBM, among others, who sell similar products.

It sounds like a gimmick, but proponents say the portable data centers can solve real problems. They are customized 20-foot or 40-foot shipping containers that vendors fill with servers and storage gear before shipping them out. Customers plug in a cooling supply, power supply and a network connection, and the mini-data centers are ready to use.

The containers provide a way for resource-constrained facilities to add compute power without having to build a new data center, which is expensive and takes a year or more. They can also be used for disaster recovery, by setting one up on the grounds of a satellite office, for example.

And powerful rack-mount servers, which generate a lot of heat, can be packed more densely in a container because the temperature can be managed more closely in the closed environment.

The HP POD will accommodate 1,800 watts per square foot, compared to about 250 watts per square foot in a normal data center, said Steve Cumings, director of infrastructure with HP's Scalable Computing and Infrastructure group.

HP's 40-foot POD will contain 22 50u server racks and be able to house up to 1,100 1u servers or 12,000 large form-factor hard drives, for a total 12 petabytes of storage, Cumings said. HP will be able to ship the products to customers six weeks after they are ordered, he said.

Sales this year will be "very low," he acknowledged, but HP expects demand to increase next year. "These are a great solution for some things, but they are a complement to traditional data centers. It's not that we expect everyone to suddenly flip over to using containers," Cumings said.

Customers will be able to put other vendors' equipment in the POD, he said, and HP will install and configure the third-party gear alongside its own. An HP subsidiary, EYP Mission Critical Facilities, will provide design and planning services for customers and the PODs will be built to order.

The IDG News Service is a Network World affiliate.