HP StorageWorks MSA2012i HP StorageWorks 2000 Modular Smart Array Reference Gu - Page 260

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. A0 & B1 WWNs, A & B volumes A1 & B0 WWNs, A & B volumes A0 & B1 WWNs, A & B volumes A1 & B0 WWNs, A & B volumes FC switch B1 WWN, B volumes A0 WWN, A volumes A0 A1 A1 WWN, A volumes B0 WWN, B volumes B0 B1 Figure C-3 FC Storage Presentation During Normal Operation (Switch Attach with Two Switches and Two Hosts) 260 HP StorageWorks 2000 Family Modular Smart Array reference guide • August 2008