A Storage Area Network (SAN) is a computer storage network composed of storage devices like disk arrays, optical jukeboxes, and tape libraries linked to a server and other devices.
A SAN is a collection of numerous fabric switches hooked up to a network. The most popular forms of SAN use Fibre Channel Fabric Protocol with Fibre Channel switches.
Disk array controllers and servers connect to the SAN. The servers in the network share the storage in the disk array controllers’ hard disks.
Every storage device in a SAN is accessible to all LAN (Local Area Network) or WAN (Wireless Area Network) servers. Any additional storage device added to a SAN will also be available for access from any server in the greater network. Here, the server is merely a pathway between the stored data and the end user.
Problems arising from the complex management of Network Attached Storage (NAS) devices brought about the invention of SANs.
NAS employs file-based protocol. In this network, storage systems are remote and the computers will need only a part of an abstract file as opposed to an entire disk block.
NAS device capacity was difficult to control. In addition, network traffic and delays were common to the Operating Systems of NAS network stacks. These problems are almost nonexistent in SANs.
SANs support different network processes such as disk mirroring, file backup and restoration, data archival and retrieval, data migration between storage devices, and data sharing among network servers.
SANs are also capable of incorporating sub-networks and Network Attached Storage (NAS) systems. Hence, data storage technology forecasts an escalation in the use of SAN over the coming years.