Network Appliance has sued Sun, alleging the infringement of seven storage and file system patents.

The Texas District Court lawsuit claims Sun infringed NetApp patents for Write Anywhere File Layout (WAFL) and RAID. NetApp claims that Sun infringed its patents when it released its Zettabyte File System (ZFS) in 2005 and allowed it to be distributed as open source software this year.

The court, under the leadership of Judge T John Ward, is known for the speediness of its decisions regarding intellectual property.

"Earlier today, Network Appliance filed a suit against Sun in defence of our intellectual property both in regards to patents that Sun alleged we had infringed as well as seven patents of ours we believe Sun infringes," said Dan Warmenhoven, CEO of Network Appliance.

The dispute follows lengthy discussions between the two companies. NetApp was first approached by StorageTek in late 2004 regarding NetApp's alleged infringement of StorageTek patents. Sun, upon acquiring StorageTek in the autumn of 2005, demanded royalties from NetApp to cover technologies it claims that NetApp uses in its products. NetApp explained that it did not encroach on any StorageTek patents.

In January of 2006, Sun renewed discussions with NetApp, noting that NetApp continued to infringe on its intellectual property. In discussions with Sun, the company explained that Sun's use of NetApp technology violated seven applicable patents.

In particular, NetApp's claim against Sun revolves around Sun's use of NetApp patented technology in ZFS.

"We are requesting damages and an injunction against Sun to prevent further distribution of patented technology in current or future versions of its ZFS technology," said Warmenhoven. "Specifically NetApp is asking the court to declare that NetApp has not infringed three of Sun's patents - that they are in fact invalid."

In bringing the lawsuit against Sun, NetApp wants to stop Sun developing and distributing ZFS. The company says that ZFS unfairly includes some of the same data consistency constructs and snap-shotting technology that NetApp's RAID arrays do.

The results of the trial could come as soon as 18 months from now, according to NetApp.

Read the background and analysis on this story by Chris Mellor here, and on his blog.