logical unit number (LUN)

A logical unit number (LUN) is a unique identifier to designate an individual or collection of physical or virtual storage devices that execute input/output (I/O) commands with a host computer, as defined by the Small System Computer Interface (SCSI) standard.

 

A LUN is central to the management of a block storage array in a storage-area network (SAN). Using a LUN can simplify the management of storage resources because access and control privileges can be assigned through the logical identifiers.