HP Surestore Disk Array 12h and FC60 - Manual (Page 120)

120 Topologies for HP-UX
High Availability, Distance, and Capacity Topology
The high availability, distance, and capacity topology expands on the high availability
topology by using cascaded HP Fibre Channel-AL Hubs to increase the distance of each
Fibre Channel-AL and the number of devices that can be interconnected on the Fibre
Channel-AL. Cascaded HP Fibre Channel-AL Hubs are two HP Fibre Channel-AL Hubs
connected together.
Each instance of this topology uses the following hardware components:
• Up to four host systems or servers
• Two Fibre Channel I/O adapters per host
• Two pairs of cascaded 10-port HP Fibre Channel-AL Hubs
• Two controller modules per disk array
• Maximum of nine dual-controller module disk arrays
• Maximum 500 m fibre optic cable distance on each connection between each host and
HP Fibre Channel-AL Hub and between each HP Fibre Channel-AL Hub and disk array,
for a total Fibre Channel-AL cable length not to exceed 5000 m
Like the high availability topology, this topology supports high availability by using
redundant Fibre Channel-ALs. If a hardware component (Fibre Channel adapter, HP Fibre
Channel-AL Hub, controller module or cables) in one Fibre Channel-AL fails, I/O
communication between hosts and disk arrays can continue through the other Fibre
Channel-AL.
The increased distance is supported by using 500 m fibre optic cable to connect each pair
of cascaded HP Fibre Channel-AL Hubs. If distance is a requirement, it is managed between
the two HP Fibre Channel-AL Hubs. The distance from hosts to HP Fibre Channel-AL Hubs
and from disk arrays to HP Fibre Channel-AL Hubs should be minimized.