IBM DS3500 Installation, User's, And Maintenance Manual page 82

The storage subsystem Fibre Channel connection consists of up to two host Fibre Channel loops. The host
Fibre Channel loops provide the fibre path for host attachment. They can consist of Fibre Channel cables,
SFP modules, host bus adapters, Fibre Channel switches, and controllers.
Fibre Channel host loop configurations:
You must determine how the host systems will connect to the storage subsystem. You can connect up to
two host systems directly to the storage subsystem. The illustrations in the following sections show
common host system configurations.
Redundant host loops:
This section provides examples of host Fibre Channel configurations.
Host Fibre Channel configurations:
This section provides the following examples of host Fibre Channel configurations.
v Single SAN fabric configuration, as shown in Figure 3-46
v Dual SAN fabric configuration, as shown in Figure 3-47 on page 3-39
v Two storage subsystems in a dual SAN fabric configuration, as shown in Figure 3-48 on page 3-39
Note: These configurations have host and drive path failover protection and are recommended for high
availability.
In Figure 3-46, the Fibre Channel switches are connected together through the Inter-Switch Link (ISL) to
form a single SAN fabric.
Host system
with two host
adapters
Fibre
Inter-Switch Link
Channel
switch
DS3500
Figure 3-46. Example of a single Fibre Channel SAN fabric configuration
In Figure 3-47 on page 3-39, the Fibre Channel switches are not connected together through an ISL. Each
switch forms its own SAN fabric. This configuration is also the configuration to use for a dual-node
cluster configuration.
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System Storage DS3500 and EXP3500: Installation, User's, and Maintenance Guide
Host system
with two host
adapters
Fibre
Channel
switch