beautypg.com

3 path failover support, Figure 4.25 alternate pathing, 4 remote sim (r-sim) reporting – Compaq 9900 User Manual

Page 93

background image

Hitachi Lightning 9900™ User and Reference Guide

79

4.5.3 Path Failover Support

The user should plan for path failover (alternate pathing) to ensure the highest data
availability. In the open-system environment, alternate pathing can be achieved by host
failover and/or I/O path failover software. The 9900 provides up to 32 fibre ports to
accommodate alternate pathing for host attachment. Figure 4.25 shows an example of
alternate pathing. The LUs can be mapped for access from multiple ports and/or multiple
target IDs. The number of connected hosts is limited only by the number of fibre-channel
ports installed and the requirement for alternate pathing within each host. If possible, the
alternate path(s) should be attached to different channel card(s) than the primary path.

The 9900 subsystem supports industry-standard I/O path failover products, including Hitachi
Dynamic Link Manager™, Sequent Multi Path, and VERITAS

®

Volume Manager/DMP. For the

latest information on failover product releases, availability, and compatibility, please
contact your Hitachi Data Systems account team.

Fibre
Adapter

LU0

LU1

CHF0

CHF1

CHA0

CHA1

Failure
occurrence

Automatic path switching

Host switching
is not required.

Capable of switching the path

LAN

Host A
(active)

Fibre
Adapter

Host B
(standby)

Fibre

Fibre

9900 Subsystem

Fibre Cable

Figure 4.25 Alternate Pathing