HP storageworks HSG80 Reference Manual page 121

OPERATING_SYSTEM=OS_name
Specifies the operating system of the host. The OPERATING_SYSTEM switch
tailors the controller's behavior for use with a particular operating system. See
your operating system specific Solution Kit to determine which value should be
used. The following values are supported: WINNT, TRU64_UNIX, VMS, HP,
HP_VSA, IBM, NETWARE, SGI, SNI, SUN, AIX_CAMBEX.
RESERVATION_STYLE=CONNECTION_BASED (default)
RESERVATION_STYLE=HBA_PORT_ID_BASED
Selection of a RESERVATION_STYLE should be based upon the capabilities of
the host operating system. See the OS kit for more details. SCSI persistent
reservations are processed differently by the HSG80 based upon the
RESERVATION_STYLE. Normal SCSI reservations (not persistent) are always
treated as CONNECTION_BASED.
When set to HBA_PORT_ID_BASED, a single persistent reservation command is
propagated to all HSG80 controller ports, thereby enabling the host to access the
unit over any available path.
When set to CONNNECTION_BASED, the persistent reservation is only valid for
the port on which it is received, thereby limiting the host access to those paths that
have been explicitly reserved.
IMPORTANT: If a particular host prefers either the CONNECTION_BASED or
HBA_PORT_ID_BASED reservation style, all the connections to that particular host must have
identical reservation style settings.
The most important advantage of this mechanism is allowing various hosts, with different
reservation style requirements, to be connected to the same HSG80 controllers in a SAN
environment.
UNIT_OFFSET
Unit offset (usually just called offset) is a decimal value that establishes the
beginning of the range of units that a host connection can access. It defines and
restricts host connection access to a contiguous group of unit numbers.
If no value is specified for the UNIT_OFFSET switch, then host connections have
default offsets as follows:
• In transparent failover mode, connections on port 1 have an offset of 0 and
connections on port 2 have an offset of 100.
• In multiple-bus failover mode, all connections have an offset of 0.
The relationship between LUN number, unit number, and offset is as follows:
LUN = unit-number – offset
HSG80 Array Controller V8.7 Command Line Interface Reference Guide
SET connection-name
2–105