LUN Masking

LUN masking performs a similar function as zoning. A LUN is a logical representation of a physical unit of storage including physical disk, physical tape drive, robotic control device, logical disk (formed by multiple physical disks with striping or RAID). LUN masking hides LUNs so that each server sees only the LUN accessible to itself. LUN masking is performed at a level just above zoning. A zone grants or restricts access only to a given port on a storage arrange, but LUN masking can take that port and grant one server access to some of its LUNs. LUN masking can be performed on 3 levels - storage array, intelligent bridges and routers, and HBA driver.