Sun officials declined to comment on pending litigation. GreenBytes could not be reached for comment.

If GreenBytes is trying to claim ownership of technology built on top of an open-source platform such as ZFS, it may be in a tough position, said Illuminati analyst John Webster.

In addition, Sun could have licensed the de-duplication technology from any of multiple vendors, Webster said. For example, Hewlett-Packard has an OEM (original equipment manufacturer) arrangement with Sepaton.

"I don't see that they would have had to ... rip off somebody in order to get it," Webster said.