A SAN island is a storage area network (SAN) that exists as a discrete, isolated entity within a larger SAN. The components of a SAN island are usually all located in the same building, or even within a single room.
SAN islands typically evolve within organizations as they grow. In a large SAN consisting of islands, the individual islands are interconnected and can share data. Connecting SAN islands together in an efficient manner can present a challenge to a growing organization. There are several ways in which SAN island interconnection can be accomplished. Fibre Channel's fast data transfer makes it a popular technology choice.
Even though a SAN island is physically located at a specific point, it may be used for more than one application, by more than one department within an organization, or by multiple organizations. Alternatively, an administrator may choose to allocate all the resources of a SAN island to one critical application. Drive sharing and data copying is common among SAN islands. Data redundancy, in which duplicates of important files or folders are contained on multiple SAN islands, is also common.