SANs provide shared, scalable storage in a networked environment. SANs can interconnect servers with storage arrays, tape libraries, or a mixture of these. Figure 1 shows an example of a SAN environment. Furthermore, SANS can provide a widely extensible architecture that enables servers and storage to be interconnected over vast distances of up to six miles or more. Central to SANs is a Fibre Channel switch or hub, which functions like a director, mapping requests and responses between the interconnected devices.
Hubs provide a loop connection scheme that shares bandwidth between the interconnected devices.
Switch-based SANs offer the highest performance. SANs are complemented by management software that centralizes control to help ease the management burden on administrators as they face aggressively ramping storage demands. This allows administrators to focus on managing the network instead of managing a menagerie of disparate components. Organizations implementing SANs recognize the need to keep data available, maximize uptime and productivity, maintain data integrity and reliability, and optimize performance with fast data access and backup. They also are looking for a storage solution that can scale with their growing business needs while simultaneously containing storage management costs by protecting investments and lowering the total cost of ownership.