ZFS compression

FreeBSD9 stable has a new option for ZFS transparent compression -  lz4. For most of my builds, I use lzjb, however lz4 appears to have some compelling advantages:

• Approximately 50% faster compression when operating on compressible data.
• Approximately 80% faster on decompression.
• Over three times faster on compression of incompressible data.
• Higher compression ratio (up to 10% on the larger block sizes).
• Performance on modern CPUs often exceeds 500 MB/s on compression and over 1.5 GB/s on decompression and incompressible data (per single CPU core).

(source: http://wiki.illumos.org/display/illumos/LZ4+Compression)