Path Failover Support; Figure 4.25 Alternate Pathing - Hitachi 9900 User And Reference Manual

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
latest information on failover product releases, availability, and compatibility, please
contact your Hitachi Data Systems account team.
Host A
(active)
Capable of switching the path
Automatic path switching
Fibre
Adapter
Failure
Fibre Cable
occurrence
CHA0

Figure 4.25 Alternate Pathing

LAN
Host switching
is not required.
Fibre
Adapter
CHA1 CHF0 CHF1
LU0
LU1
9900 Subsystem
Hitachi Lightning 9900™ User and Reference Guide
®
Volume Manager/DMP. For the
Host B
(standby)
Fibre
Fibre
79