Network Appliance, Inc. (NetApp) has filed suit in U.S. District Court in Texas against Sun Microsystems, Inc., claiming that Sun violated seven of its patents for its RAID products and its Write Anywhere File Layout (WAFL).

NetApp alleges, among other claims, that Sun infringed its patents when Sun released its Zettabyte File System (ZFS) earlier in 2005, and then permitted distribution of it this year as open source software.

NetApp is seeking damages and an injunction against Sun precluding further distribution of NetApp patented technology used in Sun’s ZFS technology. The lawsuit reportedly alleges that Sun’s ZFS includes some of the same data consistency constructs and snapshot technology that are used by NetApp’s RAID arrays.  NetApp is also hoping to have declared invalid three Sun patents that are at the core of the original disagreement.

There is a history of rancor between NetApp and Sun.  StorageTek complained to NetApp nearly seven years ago that NetApp was infringing some StorageTek patents. In 2005 StorageTek was acquired by Sun; and Sun then demanded royalty payments were owed to it for NetApp’s use of StorageTek technologies. 

NetApp insisted that it had not infringed any StorageTek patents. The quarrel continued until 2006 when Sun then claimed infringement by NetApp of three former StorageTek intellectual property rights.  NetApp then turned the tables on Sun and filed its lawsuit, claiming that Sun’s use of NetApp patented technology violated seven NetApp patents, specifically the NetApp ZFS technology.