JBOD

JBOD, short for Just a Bunch Of Disks, is a storage approach in which multiple physical disks are connected to a storage controller but are not configured into a traditional RAID array. The host can access the disks as separate logical units or, in some configurations, as a single large volume created by concatenating the disks. JBOD is often contrasted with RAID, which aggregates disks to provide redundancy or performance gains.

There are two common implementations. In the first, each disk is exposed to the operating system as an independent device; this is sometimes termed standalone disks or non-RAID mode. In the second, disks are combined into a single logical volume by concatenation or spanning, yielding a larger capacity but offering no inherent redundancy.

Advantages include simplicity, flexible capacity expansion, support for mixed drive types, and avoidance of RAID rebuilds. Disadvantages include lack of fault tolerance, potential data loss if a disk fails within a span, and the need for independent backups and file-system-level protection.

Common uses include archival storage, backup targets, test and development environments, or storage enclosures and NAS/SAN layouts where administrators prefer simple disk management or plan to manage redundancy at the file level.

See also: RAID, spanning, disk enclosure, storage architecture.