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
89HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software
Command Line Interface Reference Guide
unit-number
Identifies the designation by which the controller keeps track of the unit. This
number maps to one or more host-accessible LUNs. Unit numbers are
prefixed by D and are in the range of 0–199. How units are assigned to ports
depends on the Failover mode.
■ Transparent Failover mode:
— D0 to D99 are units assigned to port 1
— D100 to D199 are units assigned to port 2
— In Transparent Failover mode, adding unit D1 creates a logical unit
and presents it as D1 to the host on port 1. Adding unit D101 creates a
logical unit and presents it as D1 to the host on port 2.
Note: If a dual-redundant pair of controllers is in Transparent Failover mode, only
one port per controller is active.
■ Multiple-bus Failover mode:
— D0 to D199 are units visible to the hosts through both ports of both
controllers
— In Multiple-bus Failover mode, adding unit D0 creates a logical unit
that is presented to both ports on both controllers. What hosts can see
the unit is determined by parameters of the ADD CONNECTIONS
command and by the ENABLE_ACCESS_PATH or
DISABLE_ACCESS_PATH switch of the ADD UNITS command.
Refer to the detailed description of Failover modes that are contained in
the controller installation and configuration guide for further information
regarding the relationship between unit numbers and Failover mode.
All units composed from the partitioning of a storageset must be
maintained on the same controller.
The LUN number a host connection uses to access a unit is a function of
the UNIT_OFFSET switch in the ADD CONNECTIONS (or SET
connection-name) command. LUN number equals unit number
minus offset:
LUN number = unit number – offset