Sun Microsystems CEO Jonathan Schwartz acknowledges talks to resolve its patent dispute with Network Appliance have been fruitless, and Sun countersued Oct. 25, charging NetApp with violating its patents.

Sun's filing in U. S. District Court, Eastern District in Tyler, Texas, sought both an injunction against the Network Appliance product line and monetary damages.

"I have no interest in suing them. None whatever," declared Schwartz in a blog Oct. 24 as he warned of the imminence of a countersuit. But NetApp has been asking Sun to retract its ZFS file system from the open source community and restore it to proprietary status, he wrote. Schwartz said it was not possible to "unfree" what's been made freely available.

Network Appliance sued Sun Microsystems Sept. 5 for violating its ownership of NetApp's WAFL file system. Its patents were violated in the open source release of Sun's 128-bit Zettabyte File System, part of Sun's Solaris 10 operating system, the company said.

The two companies have been engaged in cross licensing discussions, a common way of resolving competing patent claims, for five years, according to NetApp's complaint submitted to the court. Patents suits are often settled with a cross licensing settlement before going to court.

The initial IP violation claim was launched by Storage Technology against Network Appliance. When Sun acquired Storage Tech, it took over the discussion between the two companies, according to NetApp's Sept. 9 complaint.

In filing its counterclaim, Sun is asking Judge Ron Clark to dismiss the NetApp suit. It's also seeking an injunction against NetApp continuing to sell its allegedly infringing products. It's asking for treble damages for NetApp's infringement, along with payment of Sun's court costs and attorneys fees.

"A non-judicial resolution is always preferable. Previous to filing our response, I've spoken to my counterpart at NetApp," said Mike Dillon, Sun's general counsel, echoing Schwartz as he announced the filing. "We had a very polite and engaged discussion ... [but] were not able to see a path to resolution."