Logical Unit Number (LUN)

The number assigned to the address space that a host uses to access a logical drive.

Each host has its own Logical Unit Number (LUN) address space and will, therefore, allow the same LUN to be used by different host groups or hosts to access logical drives in a storage subsystem. For example, Host Omaha A may access Logical Drive Engineering using LUN 5, while Host Kansas City A may also use LUN 5 to access Logical Drive Finance.

When access to a logical drive is granted to a host group, all of the hosts within the host group will share the same LUN to access the logical drive.

Important: The same LUN may not be used twice by a host group or host to access a logical drive. A unique LUN must be used.