Sun says GreenBytes, which was founded in 2007 and appears to be still in stealth mode, claims to have developed proprietary source code called ZFS+ for use with Sun's ZFS (Zettabyte File System) technology. ZFS is open source, but GreenBytes told Sun it did not intend to make its code open source, according to a lawsuit Sun filed last month.

The complaint, which Sun filed in the U.S. District Court for the Northern District of California on June 19 and amended on July 6, tells a tale of a relationship gone sour between a legendary Silicon Valley company and an innovative Rhode Island startup. The fact that Sun is in the process of being acquired by Oracle adds a further twist to the tale.

GreenBytes claims it has software that can cut storage power consumption by half. That software includes data de-duplication, a popular technology for reducing storage requirements by eliminating redundant data. The company obtained a Common Development and Distribution License (CDDL) from Sun to access and use the source code of Sun's OpenSolaris and ZFS software, and entered into a nondisclosure agreement (NDA) that allowed it to buy Sun equipment and add its own technology for sale to end-users, according to Sun.

A GreenBytes white paper still hosted on Sun's Internet domain describes ZFS+ and the Cypress NAS Filer appliance, a hardware platform based on the Sun X4500 server platform. "At GreenBytes we start with ZFS and make it better by adding a set of compelling technologies design (sic) to increase storage efficiency and dramatically reduce TCO (total cost of ownership)," the white paper says.

But in its complaint, Sun said GreenBytes courted the larger company and then turned on it.