RAID and Subsystem Architectures
Assigning Hosts to Storage
Addressing Disk Storage
JBOD Disk Subsystem
SCSI ID 0 SCSI ID 0
SCSI ID 1 SCSI ID 1
SCSI ID 2 SCSI ID 2
SCSI ID 3 SCSI ID 3
SCSI ID 4 SCSI ID 4
5 SCSI IDs
Five SCSI IDs
5 LUNs Presented as 3 LUNs
JBOD/RAID devices were addressed in the days before FC:
Basically, a LUN is a simple sub-address on a SCSI device.
JBOD present SCSI IDs as individual LUNs.
RAID may present SCSI IDs as logical groupings to form one LUN.
Fibre Channel carries SCSI, thus FC carries the same SCSI/LUN addressing
A JBOD has multiple FC ports on a loop.
A RAID subsystem may have multiple FC ports and multiple Logical
Units per FC port.