Tweeted here:
http://twitter.com/linuxquestions
The following from here:
http://wiki.github.com/behlendorf/zfs/
"Native ZFS for Linux! ZFS is an advanced file system and volume manager which was originally developed for Solaris. It has been successfully ported to FreeBSD and now there is a functional Linux ZFS kernel port too. The port currently includes a fully functional and stable SPA, DMU, and ZVOL with a ZFS Posix Layer (ZPL) on the way!"
"1.1 What about the “licensing” issue?
In a nutshell, the issue is that the Linux kernel which is licensed under the GNU General Public License is incompatible with ZFS which is licensed under the Sun CDDL. While both the GPL and CDDL are open source licenses their terms are such that it is impossible to simultaneously satisfy both licenses. This means that a single derived work of the Linux kernel and ZFS cannot be legally distributed.
One way to resolve this issue is to implement ZFS in user space with FUSE where it is not considered a derived work of the kernel. This approach resolves the licensing issues but it has some technical drawbacks. There is another option though. The CDDL does not restrict modification and release of the ZFS source code which is publicly available as part of OpenSolaris. The ZFS code can be modified to build as a CDDL licensed kernel module which is not distributed as part of the Linux kernel. This makes a Native ZFS on Linux implementation possible if you are willing to download and build it yourself."
