“Don’t use ZFS. It’s that simple. It was always more of a buzzword than anything else, I feel, and the licensing issues just make it a non-starter for me.”
What’s the licensing issue with ZFS and Linux kernel?
ZFS is open source under Common Development and Distribution License (CDDL) 1.0 whereas Linux kernel is licensed under the GNU General Public License (GPL) 2.0.
These two open source licenses are not fully compatible with each other. As noted by PCWorld, if ZFS with this license is included in the Linux kernel, this would mean that kernel+ZFS is a derivative work of the (original ZFS-less) Linux kernel.
Torvalds doesn’t trust Oracle
While the whole derivative thing is a matter of debate for legal and licensing experts, Torvalds is skeptical of Oracle. Oracle has a history of suing enterprises for using its code. Remember Oracle vs Android lawsuit over the use of Java?
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.
And I’m not at all interested in some “ZFS shim layer” thing either that some people seem to think would isolate the two projects. That adds no value to our side, and given Oracle’s interface copyright suits (see Java), I don’t think it’s any real licensing win either.
Torvalds doesn’t want Linux kernel to get into legal troubles with Oracle in future and hence he refuses to include ZFS in mainline kernel until Orcale provides a signed letter that a kernel with ZFS will be under GPL license.
And honestly, there is no way I can merge any of the ZFS efforts until I get an official