NetApp Sues Sun over File System IP

Sun's Zetabyte File System and NetApp's WAFL storage systems are at the center of a lawsuit filed Sept. 5.

NetApp filed a lawsuit on Sept. 5 against Sun Microsystems seeking damages and a permanent injunction against the company, claiming Sun has infringed on several patents regarding NetApps home-grown WAFL file system.

NetApp claims Suns ZFS (Zetabyte File System), which is included in Suns Unix-derived Solaris operating system, is patterned directly after its own WAFL (Write Anywhere File Layout) file system.

NetApp characterized the suit as a defensive step after Sun sought to charge NetApp to license its technology, NetApp officials said. In response, NetApp reviewed its own list of patents and identified those it believes Sun infringes, they said.

This is not a case of stolen or copied code—from either inside or outside sources, NetApp CEO Dan Warmenhoven told a conference call of journalists and analysts.

"Were not saying they stole code from us," Warmenhoven said in answer to a question from eWEEK. "Were saying that there are clear patterns of techniques that we use in our file system that are in ZFS, and that we want Sun to stop using it commercially."

NetApps suit, filed in Federal District Court in Marshall, Texas, seeks a declaration that it is not infringing three of Suns U.S. patents and that those patents are invalid. In addition, the suit also seeks a ruling that Sun infringed upon seven NetApp U.S. patents pertaining to data processing systems and related software within ZFS.


To read about Microsofts claims that open source technology has violated hundreds of their patents, click here.

WAFL was developed in the early 1990s at NetApp, based in Sunnyvale, Calif. Both WAFL and the 128-bit Solaris ZFS are based on a transactional object model that removes most of the traditional constraints associated to I/O operations, resulting in substantial performance gains.

"Heres what creators of ZFS have to say: The file system that has come closest to our design principles, other than ZFS itself, is WAFL … the first commercial file system to use the copy-on-write tree of blocks approach to file system consistency, " NetApp co-founder and executive vice president Dave Hitz wrote in an Aug. 5 blog. "One of the first patents I filed at NetApp describes this copy-on-write tree of blocks technique in detail."

Hitz said "it looks like ZFS was a conscious reimplementation of our WAFL file system, with little regard to intellectual property rights."

Like many large technology companies, Sun has been using its patent portfolio as a profit center, Hitz wrote.

"About 18 months ago, Suns lawyers contacted NetApp with a list of patents they say we infringe, and requested that we pay them lots of money [to license the technology]. We responded in two ways. First, we closely examined their list of patents. Second, we identified the patents in our portfolio that we believe Sun infringes," he wrote.

NetApp made major efforts to resolve these issues amicably, Warmenhoven said. "Unfortunately, Sun shifted from an aggressive position to not being responsive, leaving important issues unresolved," he said.

When the Sun lawyers stopped their requests for license fees and didnt return calls from NetApp, Warmenhoven said, thats when NetApp decided to act.


Read more here about Suns Solaris 10.

"With respect to Suns patent claims, our lawsuit explains that we do not infringe, and—in fact—that they are not even valid. As a result, we dont think we should be paying Sun millions of dollars."

NetApp wants to stop ZFS from being used in all commercial development. However, because Sun released ZFS to the open-source community last winter, it is impossible to stop an individual or company from using it.

Warmenhoven said he believes Sun unfairly distributes ZFS technology to third parties to induce the adoption and distribution of the infringing technology in their products without informing them of applicable NetApp patents.

"Its okay for a research institution or single individual to use it; thats not a problem," Warmenhoven told eWEEK in a conference call. "We just want Sun to stop using it to make money. As far as other companies using ZFS in commercial production situations, thats a complex legal question that we cant answer right now."

Warmenhoven said that the suit was filed in the federal court in Texas because of "speed. They have a record for fast resolution times there ... they have IP experience inside that court that will help move the process along faster."

Sun spokeswoman Kristi Rawlinson provided the following response statement late in the day Sept. 5:

"NetApps legal attack against Suns open source ZFS solution which is freely available in the marketplace is a clear indication that NetApp considers Sun technology a threat, and is a direct attack on the open source community.

"ZFS is the fastest-growing storage virtualization technology in the marketplace, and NetApps attempt to use patent litigation to inhibit the meteoric rise of open source technologies like ZFS is tantamount to being unhappy with gravity. As Sun knows well, and NetApps customers obviously recognize, innovation works better than litigation.

"Many of the claims raised in the lawsuit are factually untrue. For example, it was NetApp who first approached Sun seeking to acquire the Sun patents NetApp is now attempting to invalidate. It is unfortunate that NetApp has now resorted to resolving its business issues in a legal jurisdiction (East Texas) long favored by patent trolls.

"Bottom line, Sun indemnifies its customers, and stands behind the innovations we deliver to the marketplace."


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Chris Preimesberger

Chris J. Preimesberger

Chris J. Preimesberger is Editor-in-Chief of eWEEK and responsible for all the publication's coverage. In his 13 years and more than 4,000 articles at eWEEK, he has distinguished himself in reporting...