ZFS is an advanced file system, jointly-developed by Sun Microsystems. As an open-source product, it is also developed via the community under the Common Development and Distribution License (CDDL).

ZFS differs from traditional file systems, such-as NTFS and FAT, by negating the requirement for hard disks to first be logically joined by a volume manager (a-la RAID) or partitioned with legacy partition tables. Empty block devices (a physical disk), single partitions from existing volumes and single files on an existing file system, can all be added to the same storage pool. Once created, users are able to seamlessly utilise the storage capacity provided by the sum of all member devices, partitions and files, as if it were one, single storage entity.

The ZFS file system provides many advanced features, without requiring additional hardware or software: RAID volume creation, low-cost snapshots, scrubbing of the file system, quotas and access control lists. At a technical level, ZFS also continues to excel in many areas. However, the exact details of these improvements are well beyond the scope of this glossary entry.

Blueberry Consultants have adopted the ZFS file system as an integral part of their data storage infrastructure. After considering many white box NAS and SAN storage solutions, ZFS (provided by Nexenta, an OpenSolaris distribution) presented a flexible, high-performance solution that promises to provide the increased capacity for future storage expansion.