The StorageTek 6140 array houses two controllers; each controller has four host ports. The cabling approach is the same as shown in Figure 2–1, but it can support up to four nodes in a direct-attach configuration.
Figure 2–2 shows a switched configuration for a two-node storage array.
You can connect one or more hosts to a storage array. Figure 2–3 shows an example of a direct host connection from each data host with dual HBAs.
For maximum hardware redundancy, you should install a minimum of two HBAs in each host and distribute I/O paths between these HBAs. A single, dual-port HBA can provide both data paths to the storage array but does not ensure redundancy if the HBA fails.
Figure 2–4 shows that three hosts can be connected directly or through a switch.