ZFS

ZFS is a filesystem originally developed by Sun Microsystems. It has sophisticated features including software RAID, deduplication, and data compression.

On Linux
ZFS cannot be incorporated into the Linux kernel distribution, due to license incompatibilities. However, a native Linux port of it is availble, and was declared to be production-ready as of March 2013.

Links

 * Wikipedia article
 * ZFS on Linux
 * Article about production-ready ZFS for Linux