Fibre Channel is designed from the ground up to be highly available. Fibre Channel can be set up with redundant pairs of fibre to the host without a significant effort. Storage arrays with redundant controllers are readily available and can be failed over seamlessly.
Fibre Channel switches can be utilized to provide a networked and redundant storage environment. When planning for high availability we always want to deploy a redundant pair of switches. Each host should be set up with dual port Fibre Channel HBAs. In this configuration, we connect the first HBA to the first switch and the second HBA to the second switch. Storage arrays are also hooked up in a similar manner with fibre running to both switches. Single controller storage arrays should come with two Fibre Channel connectors that can be used for this purpose. The following diagram is a scenario where a single switch has failed:
Here we see that...