IBM DS4700 manual Fibre channel connections, Fibre channel host loop configurations

Host 1, Host Adapter 1 and 2 Host 4, Host Adapter 1 and 2

4 3 2 1

1 2 3 4

Host 2, Host Adapter 1 and 2 Host 3, Host Adapter 1 and 2

ds470024

Figure 86. Cabling diagram for four redundant host connections

For examples of redundant, partially-redundant, and non-redundant host and drive loop configurations, see “Fibre channel host loop configurations.”

Fibre channel connections

The storage subsystem fibre channel connection consists of up to four host fibre-channel loops and a redundant drive fibre-channel loop. The host fibre-channel loops provide the fibre path for host attachment. They can consist of fibre-channel cables, SFPs, host bus adapters, fibre-channel switches, and RAID controllers. The redundant drive fibre-channel loop provides the fibre path from the DS4700 Express Storage Subsystem to the hard disk drives (HDDs) in the storage expansion enclosures. The redundant drive fibre-channel loop consists of the DS4700 Express Storage Subsystem, the storage expansion enclosures, fibre-channel cables, and SFPs.

The DS4700 Express supports redundant drive channel loop configurations. You can build a redundant drive channel loop by connecting one or more storage expansion enclosures to the redundant RAID controllers. Then, use dual fiber-optic cables to connect one storage expansion enclosure to another in a daisy-chain. For more information, see “Connecting storage expansion enclosures to the DS4700 Express” on page 68.

Fibre channel host loop configurations

You must determine how the host systems will connect to the storage subsystem. You can connect up to four host systems directly to the storage subsystem, or you can connect more than two hosts to the fibre channel storage subsystem through switches. The illustrations in the following sections show common host system configurations.

Chapter 3. Cabling the storage subsystem 107