HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Command Line Interface Reference Guide (EK-G80CL-RA. C01, March 2005)

CLI Command Descriptions
61HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software
Command Line Interface Reference Guide
Note: If a controller pair is switched from Transparent Failover mode to Multiple-bus
Failover mode, the unit offsets for Transparent Failover mode remain in effect.
The LUN number equals the unit number minus the offset:
LUN number = unit number – offset
■ Logical unit number or LUN number = the logical unit number presented
to the host connection.
■ Unit number = the number assigned to the unit in the ADD UNITS
command. This is the number by which the unit is known internally to the
controllers.
For example, a system has three host connections, each of which can see 8
LUNs. Each connection designates its LUNs as 0 through 7. To define for
each of these connections a block of 8 units, set the offset for each connection,
as follows:
CLI>SET SERVER1 UNIT_OFFSET=0
CLI>SET SERVER2 UNIT_OFFSET=10
CLI>SET SERVER3 UNIT_OFFSET=120
Note: It is not necessary to use offsets that are divisible by 10, but it makes things
simpler.
The effects of these offset assignments are as follows:
■ Server1 accesses units D0 through D7, which it sees as LUNs 0
through 7.
■ Server2 accesses units D10 through D17, which it sees as LUNs 0
through 7.
■ Server3 accesses units D120 through D127, which it sees as LUNs 0
through 7.
If you are assigning unit numbers and offsets consider the following. If the
SCSI_VERSION switch of the SET THIS CONTROLLER or SET OTHER
CONTROLLER command is set to SCSI-3, the command console LUN (CCL)
is presented as LUN 0 to every connection, superseding any unit assignments.
For more information, see the ADD UNITS command.