What Is a Storage Area Network?

The Storage Area Network (SAN) uses Fibre Channel (FC for short), which is different from Fiber Channel (Fiber Channel) technology. It connects storage arrays and server hosts through FC switches to establish an area network dedicated to data storage. After more than ten years of history, the SAN has become quite mature and has become the de facto standard in the industry (but the fiber switching technologies of different manufacturers are not exactly the same, and their servers and SAN storage have compatibility requirements).

The Storage Area Network (SAN) uses Fibre Channel (FC for short), which is different from Fiber Channel (Fiber Channel) technology. It connects storage arrays and server hosts through FC switches to establish an area network dedicated to data storage. After more than ten years of history, the SAN has become quite mature and has become the de facto standard in the industry (but the fiber switching technologies of different manufacturers are not exactly the same, and their servers and SAN storage have compatibility requirements).

SANs focus on issues specific to enterprise storage. The two root causes of the problems encountered by current enterprise storage solutions are: the structural limitations caused by the close integration of data and application systems, and the limitations of the Small Computer System Interface (SCSI) standard. Most analysts believe that SAN is the enterprise storage solution of the future, because SAN is easy to integrate, it can improve data availability and network performance, and it can also reduce management tasks.

Chinese name

Storage area network

Foreign name

(Storage Area Network and SAN Protocols

Subject

IT

Field

cloud storage

Storage area network structure

A SAN is actually a dedicated network built for storage that is independent of the TCP / IP network. At present, general SANs provide transmission rates from 2Gb / S to 4Gb / S. At the same time, the SAN network exists independently of the data network, so the access speed is fast. In addition, SANs generally use high-end RAID arrays, which makes the performance of the SAN in several professional Dominate the storage solution.
Because the foundation of a SAN is a private network, it is highly scalable. It is very convenient whether you add a certain amount of storage space in a SAN system or add several servers that use storage space. Through the SAN interface tape drive, the SAN system can conveniently and efficiently implement centralized backup of data.

At present, common SANs include FC-SAN and IP-SAN. Among them, FC-SAN forwards the SCSI protocol through the Fibre Channel protocol, and IP-SAN forwards the SCSI protocol through the TCP protocol. ^[1]

Storage area network advantages

SANs provide an easy way to connect to existing LANs and support the widely used SCSI and IP protocols over the same physical channel. SANs are not limited by today's mainstream SCSI-based storage architecture layouts. Of particular importance is that with the explosive growth of storage capacity, SANs allow enterprises to independently increase their storage capacity.

The structure of the SAN allows any server to be connected to any storage array, so that the server can directly access the required data regardless of where the data is placed. Because of the use of fiber optic interfaces, SANs also have higher bandwidth.

Because SAN solutions strip storage away from basic functions, running backup operations eliminates the need to consider their impact on overall network performance. The SAN solution also simplifies management and centralized control, especially when all storage devices are clustered together. Finally, the fiber-optic interface provides a 10-kilometer connection length, which makes it very easy to achieve physically separate, non-machine room storage. ^[2]

Storage area network limitations

Cost and complexity, especially in Fibre Channel, are especially noticeable. In the case of using Fibre Channel, the reasonable cost is about 1 Gigabit or 2 Gigabits, which needs about 50,000 to 60,000 US dollars. From another perspective, although the new iSCSI-based SAN solution only costs about 20,000 to 30,000 US dollars, its performance cannot be compared with Fibre Channel. The difference in price is mainly due to the fact that iSCSI technology uses gigabit Ethernet hardware that is now mass-produced, while Fibre Channel technology requires specific expensive equipment.

Storage area network applicable environment

SANs are mainly used in working environments with large storage volumes, such as ISPs, banks, etc. The high cost and standards have not been determined have affected the SAN market. However, with the increase in the business volume of these users, SANs have broad application prospects .