In the recent “Moderated Discussions” forum at realworldtech.com, Linus Torvalds warned kernel developers against adding a module for the ZFS filesystem until Oracle were to re-license the code for mainline inclusion.

He was answering a user’s question about a year-old kernel maintenance controversy, as reported by Phoronix.

“Honestly, there is no way I can merge any of the ZFS efforts until I get an official letter from Oracle,” he wrote. “Other people think it can be OK to merge ZFS code into the kernel and that the module interface makes it OK, and that’s their decision. But considering Oracle’s litigious nature, and the questions over licensing, there’s no way I can feel safe in ever doing so.”

Designed by Sun Microsystems, the ZFS filesystem is now owned by Oracle. For the uninitiated, it has long been licensed under Sun’s Common Development and Distribution License (CDDL). The Linux kernel, on the other hand, is licensed under GNU General Public License (GPL).

Here are his final words on the matter: “Don’t use ZFS. It’s that simple.”