Storage Area Network (
SAN
for short ) uses Fibre Channel (
FC
for short , which is different from Fiber Channel) technology, connects
storage
arrays and server
hosts
through FC switches, and establishes an area network dedicated to
data storage.
After more than ten years of development, SAN has become quite mature and has become a de facto standard in the industry (but the fiber switching technologies of various manufacturers are not exactly the same, and their servers and SAN storage have compatibility requirements).
SANs focus on the unique issues of enterprise storage. Two sources of problems with current enterprise storage solutions are the structural constraints imposed by the tight integration of data and application systems, and the limitations of the
Small
Computer System Interface (SCSI) standard. Most analysts see SANs as the enterprise storage solution of the future because SANs are easy to integrate, improve data availability and network performance, and reduce administrative tasks.
structure
A SAN is actually a dedicated network that is established for storage and is independent of the TCP/IP network. At present, the general SAN provides a transmission rate of 2Gb/S to 4Gb/S. At the same time, the SAN network exists independently of the data network, so the access speed is very fast. In addition, the SAN generally adopts a high-end RAID array, which makes the performance of the SAN in several professional It is the leader in storage solutions.
Because the SAN is based on a dedicated network, it is highly scalable. It is very convenient to add a certain storage space to a SAN system or to add several servers that use storage space. Through the tape drive of the SAN interface, the SAN system can conveniently and efficiently realize centralized data backup.
Because the SAN is based on a dedicated network, it is highly scalable. It is very convenient to add a certain storage space to a SAN system or to add several servers that use storage space. Through the tape drive of the SAN interface, the SAN system can conveniently and efficiently realize centralized data backup.
At present, common SANs include FC-SAN and IP-SAN, in which FC-SAN forwards SCSI protocol through Fibre Channel protocol, and IP-SAN forwards SCSI protocol through TCP protocol.
advantage
SANs
provide an easy way to connect to an existing
LAN
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 architectures
. Of particular importance,
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 no matter where the data resides, the server has direct access to the data it needs. SANs also have higher bandwidth due to the use of fiber optic interfaces.
Because SAN solutions strip storage functions from basic functions, backup operations can be run without regard to their impact on the overall performance of the network. SAN solutions also simplify management and centralized control, especially when all storage devices are clustered together. Last but not least, the fiber optic interface provides a 10-kilometer connection length, which makes it very easy to implement physically separate, out-of-room storage.
limited
Cost and complexity, especially in Fibre Channel, these deficiencies are particularly pronounced. In the case of Fibre Channel, a reasonable cost is about $50,000 to $60,000 for 1 gigabit or two gigabits. From another perspective, although new iSCSI-based SAN solutions cost about $20,000 to $30,000, their performance cannot be compared to 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.
Applicable environment
SANs are mainly
used
in work environments with large amounts of storage, such as ISPs, banks, etc. Problems such as high costs and undetermined standards have affected the SAN market. However, with the increase in the business volume of these users, SANs also have broad application prospects. .