Specifications

134 IBM Flex System p260 and p460 Planning and Implementation Guide

Consider the scenario of dual-FC, dual-SAN switch redundancy, connected with

storage attached through a SAN for an p460. In this scenario, the OS has four

paths to each storage, and the behavior of the multipathing driver might vary,

depending on the storage and switch type. This scenario is one of the best

scenarios for high availability. The two adapters prevent an adapter fault, the two

switches prevent the case of a switch fault or firmware upgrade, and, as the SAN

has two paths to each storage device, the worst scenario is the failure of the

complete storage. Figure 5-4 shows this scenario.

Figure 5-4 Dual-FC and dual-SAN switch redundancy connection, as applied to the IBM Flex System p460

Compute Node

This configuration might be improved by adding multiple paths from each Fibre

Channel switch in the chassis to the SAN, which protects against a cable failure.

Chassis

Compute node

DS3400 Storage

V7000 Storage

SAN switch

Storage Area

Network

FC switch

FC adapter