Sun Microsystems, responding to a lawsuit it faces from Network Appliance over Sun’s ZFS (Zettabyte File System), plans to countersue, Sun CEO Jonathan Schwartz said in his blog on Wednesday.While stressing he has no interest in suing Network Appliance, Schwartz said Sun has no choice but to respond in court. Later this week, Sun plans to request a permanent injunction to remove Network Appliance filer products from the marketplace and seek monetary damages. Half of these proceeds would be earmarked for efforts to promote free software and patent reform, with money going to the Software Freedom Law Center and the Peer to Patent initiative. Network Appliance filed suit in September claiming ZFS violates the company’s patents. Previously, Sun said Network Appliance had been using some of its own technology acquired when Sun bought StorageTek. Sun demanded royalties from Network Appliance.Network Appliance could not be immediately reached for a response to Sun’s plans on Wednesday afternoon.