A storage area network or SAN is a logical computer network that provides remote access to unified, consolidated, block-level data storage over a local network. SANs are used primarily to access data storage devices like disk arrays and tape drives from multiple servers, so the devices seem to the operating system like directly attached storage. The network has features such as virtualization, address management, and policy-based routing, all of which allow different devices in the same network to operate in different ways. For example, while one disk drive in a local network may be connected to several other drives in a different network, a SAN has virtual networking between them. The physical address of a networked SAN is given by the manufacturer of the SAN device.
There are three basic types of SANs: enterprise, consumer, and central. An enterprise network has some storage-oriented servers that are connected through the network to a central database management system. Consumer networks have a single storage-area network with various interface units connected to it. Centralized networks, sometimes called logical grids, are large collections of local storage appliances that are connected through routers or hubs over a private network. All these three types have different ways of storing information about files and networks and they have different reliability and security properties.
Some considerations must be taken into account when planning a storage area network. First, any existing wiring between the nodes in the network must be taken care of. Second, extra equipment needs to be brought into the area where the SAN is being installed. The amount of equipment that is needed is based on the total capacity of the SAN and the traffic pattern expected for that location.
Thirdly, certain physical solutions are needed to support the installation of a storage area network. Since …