“A recent discussion on the lkml examined the possibility of a
Linux implementation of Sun’s ZFS. It was pointed out that the file
system is released under the GPL-incompatible CDDL, and that Sun
has filed numerous patents to prevent ZFS from being reverse
engineered. Max Yudin pointed out, ‘according to Jeff Bonwick’s
blog Sun issued 56 patents on ZFS, but I have no idea what they
patented. Sorry, binary compatible ZFS reimplementation with GPL
license might not be legal.’ David Litwin noted that he had been
told by a ZFS developer to talk to Linux developers to see about
getting non-GPL’d code included with the kernel. Theodore T’so
replied, ‘that was totally useless answer from the ZFS developers.
What he should have told you is to contact Sun management, since
they are the only ones who can decide whether or not to release ZFS
under a GPL license, and more importantly, to give a patent license
for any patents they may have filed in the course of developing
ZFS…'”