Storage Area Network : What is SAN and How it Works

Storage Area Network and storage network are known in the field of data processing for a network of disk subsystems and tape libraries to server systems. Storage Area Networks are for serial, continuous high-speed transfers of large data sets. Storage Area Network are used for high-availability, high performance installations for cost reduction.

Development and Principle of Storage Area Network

Structurally, a Storage Area Network is constructed analogously to a Local Area Network (LAN) : there are hubs , switches and routers.  A Storage Area Network is an extension of direct attached storage (DAS) , which is disk storage allocated to a server over a network. The latter functionality is mainly implemented in Storage Area Network -compatible disk arrays. While a point-to-point connection between a server and a directly connected data storage forms, it allows a Storage Area Network, multiple servers to multiple storage systems to connect via a network, even over long distances. Storage Area Network is designed to manage the problem of dedicated hard disk drives in server systems and network-attached storage systems (NAS), because in these systems, an efficient and flexible use of storage capacity is limited.

Storage Area Network are now working with transfer rates of up to 16 Gbit/s. Transfer rates of (theoretically) 1.6 GB / s is possible. In addition, the concept of multi-pathing , which is consistently followed in Storage Area Network.

Storage Area Network and Virtualization

A major advantage of Storage Area Network is the virtualization of existing disk subsystems. The existing mass storage can virtually act as a single hard disk. The single server systems will be on this virtual hard disk partitions assigned to this server on the host, bus adapter can incorporate as a separate disk. The available space can be used is much more effective and centrally managed, since it is possible at any time during operation to change the size of the allocated memory area for the servers in Storage Area Network.