In today’s terms, the technical description of a SAN (Storage Area Network) is a collection of computers and storage devices, connected over a high-speed optical network and dedicated to the task of storing and protecting data. In a nutshell, you use a SAN to store and protect data.
A SAN uses the SCSI (Small Computer Storage Interconnect) and FC (Fibre Channel) protocols to move data over a network and store it directly to disk drives in block format.
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Today, that high-speed network usually consists of fiber-optic cables and switches that use light waves to transmit data with a connection protocol known as Fibre Channel. (A protocol is a set of rules used by the computer devices to define a common communication language.) More and more, regular Internet protocol (IP)–based corporate networks, and even the Internet, are being used as the network part of a SAN.
Nowadays Internet is the part of SAN
- IP networks that are already in place can be used by other storage connection protocols such as iSCSI (internet Small Computer Storage Interconnect) to move and store data.
- Using a network to create a shared pool of storage devices is what makes a SAN different. A SAN moves data among various storage devices, allows sharing data between different servers, and provides a fast connection medium for backing up, restoring, archiving, and retrieving data.
- SAN devices are usually bunched closely in a single room, but they can also be connected over long distances, making a SAN very useful to large companies. Many of today’s SAN components are pretty much plug-and-play. To create a simple SAN, you just connect all the devices together with cables, and off you go. Creating larger SANs with many storage switches can become complex.