HP StorageWorks 2000 Modular Smart Array Reference Guide (481599-003, August 2008)

260 HP StorageWorks 2000 Family Modular Smart Array reference guide • August 2008
FC Switch Attach Configuration
The topology only affects how mapped volumes and port WWNs are presented if
one controller fails. Whichever topology is used, each data host has dual-ported
access to volumes through both controllers.
■ Failover in a switch attach, loop configuration. If one controller fails in a
switch attach configuration using loop topology, the host ports on the surviving
controller present the port WWNs for both controllers. Each controller’s mapped
volumes remain accessible.
■ Failover in a switch attach, point-to-point configuration. If one controller fails
in a switch attach configuration using point-to-point topology, the surviving
controller presents its mapped volumes on its primary host port and the mapped
volumes owned by the failed controller on the secondary port.
In a high-availability configuration, two data hosts connect through two switches to
a dual-controller storage system and the host port interconnects are disabled.
The following figure shows how port WWNs and mapped volumes are presented
when both controllers are active.
Figure C-3 FC Storage Presentation During Normal Operation (Switch Attach
with Two Switches and Two Hosts)
FC switch
A0 A1
B0 B1
B0 WWN,
B volumes
B1 WWN,
B volumes
A1 WWN,
A volumes
A0 WWN,
A volumes
A0 & B1 WWNs,
A & B volumes
A1 & B0 WWNs,
A & B volumes
A0 & B1 WWNs,
A & B volumes
A1 & B0 WWNs,
A & B volumes