logical unit number การใช้

In this instance, " back-end " refers to a logical unit number ( LUN ) that is not presented to a computer, or host system for direct use.
I want to know what exactly a Storage Area Network is-I am aware that a SAN contains HDDs which hold volumes which are attached to servers via logical unit numbers.
Each device on the SCSI bus is assigned a unique SCSI identification number or ID . Devices may encompass multiple logical units, which are addressed by logical unit number ( LUN ).
Internally, LIO does not initiate sessions, but instead provides one or more Logical Unit Numbers ( LUNs ), waits for SCSI commands from a SCSI initiator, and performs required input / output data transfers.
In redundant array of independent disks ( RAID ) devices and storage area networks ( SANs ) and where logical drives ( logical unit numbers, LUNs ) are composed via LUN virtualization and aggregation, LBA addressing of individual disk should be translated by a software layer to provide uniform LBA addressing for the entire storage device.