what is san storage

A Storage Area Network (SAN) is a specialized, high-speed network that provides network access to storage devices. SANs are typically composed of hosts, storage elements, and a communication infrastructure, which provides physical connections, allowing any-to-any device to bridge across the network using interconnected elements, such as switches and directors. SANs are primarily used to access data storage devices, such as disk arrays and tape libraries from servers so that the devices appear to the operating system as direct-attached storage. SAN technology addresses advanced enterprise storage demands by providing a separate, dedicated, highly scalable high-performance network designed to interconnect a multitude of servers to an array of storage devices. SANs allow for the automatic backup of data, and the monitoring of the storage as well as the backup process. SANs are block-based storage, leveraging a high-speed architecture that connects servers to their logical disk units (LUNs) . A LUN is a range of blocks provisioned from a pool of shared storage and presented to the server as a logical disk. The server partitions and formats those blocks—typically with a file system—so that it can store data on the LUN just as it would on local disk storage. SANs make up about two-thirds of the total networked storage market.