HP StorageWorks HSG80 ACS Solution Software V8.8 for Novell NetWare Installation and Configuration Guide (AA-RV1MA-TE, March 2005)

Planning a Subsystem
53HSG80 ACS Solution Software V8.8 for Novell NetWare Installation and Configuration Guide
Restricting Host Access by Offsets
Offsets establish the start of the range of units that a host connection can access.
For example:
In Figure 16, assume both host connections on port 2 (connections BLACK1B2
and BROWN1B2) initially have the default port 2 offset of 100. Setting the offset
of connection BROWN1B2 to 120 presents unit D120 to host BROWN as LUN 0.
SET BROWN1B2 UNIT_OFFSET=120
Host BROWN cannot see units lower than its offset, so it cannot access units
D100 and D101. However, host BLACK can still access D120 as LUN 20 if the
operating system permits. To restrict access of D120 to only host BROWN,
enable only host BROWN’s access, as follows:
SET D120 DISABLE_ACCESS_PATH=ALL
SET D120 ENABLE_ACCESS_PATH=
BROWN1B2
Note: HP recommends that you provide access to only specific connections, even if
there is just one connection on the link. This way, if new connections are added, they
do not have automatic access to all units.
Restricting Host Access in Multiple-Bus Failover Mode
In multiple-bus mode, the units assigned to any port are visible to all ports. There
are two ways to limit host access in multiple-bus failover mode:
■ Enabling the access path of selected host connections
■ Setting offsets
Enabling the Access Path of Selected Host Connections
Host access can be limited by enabling the access of certain host connections and
disabling the access of others. This is done through the
ENABLE_ACCESS_PATH and DISABLE_ACCESS_PATH switches of the
ADD
UNIT
(or SET unit) commands. Access path is a unit switch, meaning it must be
specified for each unit. Default access means that the unit is accessible to all hosts.
It is important to remember that at least two paths between the unit and the host
must be enabled in order for multiple-bus failover to work.