Backblaze provides unlimited online storage and a Mac OS X- or Windows-native backup client for $5. At that price, says Backblaze co-founder and CEO Gleb Budman, many have begun to wonder how the company can afford to stay in business.

"We looked at how other companies price it--everything from Amazon's S3 to enterprise-level storage systems from EMC and NetApp," Budman told . "They were easily 10 times more expensive, if not more, than the raw components."

That's when Backblaze decided that a DIY solution was the right way to go, and they've published the spec as on their Web site. The "Backblaze Storage Pod" system comprises a custom container that occupies 4U in a standard equipment rack. Inside are 45 hard disk drives, four Serial ATA (SATA) controller cards, an Intel motherboard and processor, 4GB RAM and two power supplies.

Each box runs Linux operating in 64-bit mode and the , a freeware journaling file system.

The 67TB Backblaze Storage Pods are individually accessed using the HTTPS protocol through , an open source implementation of the Java Servlet and JavaServer Pages.