Two different projects are in full swing developing a native port of the ZFS file system to Linux. Currently, the only available ZFS for Linux is based on FUSE (running file systems in user space, not kernel space). Running with FUSE means a significant penalty in speed.
One ZFS project is being done at Lawrence Livermore National Laboratory and is driven by Brian Behlendorf; the other project is being done by KQ Infotech. OSNews had a good article about the LLNL project.
Phoronix is reporting that KQ Infotech announced they would be releasing source code in September. Unfortunately, the project apparently only supports 64-bit Linux, and does not support data de-duplication and other newer features.
The writer is also unimpressed by ZFS overall; there is mention of BtrFS as being better. What is truly interesting is that both file systems are now are under the Oracle umbrella – BtrFS since the beginning, and ZFS as part of the Sun acquisition.
On top of this, Oracle and NetApp have resolved the lawsuit over ZFS, removing the clouds that had hung over ZFS.
These are interesting times for ZFS. If you don’t understand what the fuss is all about, Paul Rubens has a quick overview, and Sun’s ZFS team has an excellent slide presentation on ZFS. There are more ZFS resources available from the OpenSolaris ZFS Community.
UNIX Administratosphere 
Just a minor note: the “quick overview” link has the same target as the previous “lawsuit resolved” link, you may want to fix that.
Thanks and hi! 😉
Thanks for the note! Link has been fixed….