ZFS is an advanced modern filesystem from Sun Microsystems, originally designed for Solaris/OpenSolaris.

ZFS has many features which can benefit all kinds of users - from the simple end-user to the biggest enterprise systems:

• Provable integrity - it checksums all data (and metadata), which makes it possible to detect hardware errors (hard disk corruption, flaky IDE cables, etc...)
• Atomic updates - means that the on-disk state is consistent at all times, there's no need to perform a lengthy filesystem check after forced reboots or power failures
• Instantaneous snapshots and clones - it makes it possible to have hourly, daily and weekly backups efficiently, as well as experiment with new system configurations without any risks
• Built-in (optional) compression
• Highly scalable
• Pooled storage model - creating filesystems is as easy as creating a new directory. You can efficiently have thousands of filesystems, each with it's own quotas and reservations, and different properties (compression algorithm, checksum algorithm, etc...)
• Built-in stripes (RAID-0), mirrors (RAID-1) and RAID-Z (it's like software RAID-5, but more efficient due to ZFS's copy-on-write transactional model).
• Many others (variable sector sizes, adaptive endianness, ...)