HSG80 ACS Solution Software Version 8.7 for Compaq Tru64 UNIX Installation and Configuration Guide

Planning a Subsystem
1–24 HSG80 ACS Solution Software Version 8.7 for Compaq Tru64 UNIX Installation and
Configuration Guide
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: StorageWorks 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 will 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
Enable 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.