Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide

Troubleshooting 6–7
Failure Modes of a DT System in Normal
Operation
Table 6–1 details the failure modes of a DT system operating in normal mode. While this
table concentrates on the major failure possibilities, keep in mind that there are several
other combinations that may occur. In most cases, when there is a loss of a major
component, a failover is necessary to continue operation.
Table 6–1 Failure Modes of a DT System with Normal Operation
Initiator Host
Target Host
Initiator Switch A Initiator Switch B
Target Switch A Target Switch B
Initiator Controller A Initiator Controller B
Target Controller A Target Controller B
Failure Mode
Loss of:
Action
X Applications Failover; Repair Host
X Remote host Repair Host
X X Both sites Failover not possible; Repair Hosts
X Data path Repair Switch
X Data path Repair Switch
X Data path Repair Switch
X Data path Repair Switch
X X Data access Failover; Repair Switches
XX
Remote copy
set targets
Repair Switches;
Target member must incur
mini-merge or full copy
X X Data path Repair Switches
X Data path Repair Controller
X Data path Repair Controller
X Data path Repair Controller