A storage area network or SAN is a computer network created to provide block level storage to computers not directly linked to storage-devices or driver raise. The storage in a Storage Area Network is reachable by all the servers on the network. SAN storage is divided into logical storage pools or volumes that can be allocated to specific host-servers.
SAN-interfaces comprise fiber channel, iSCSI and Fiber Channel over Ethernet. Fiber channel is a high-speed networking technology mainly used for computer-storage Apps. Almost all of the large data centers that have employed SAN technology have implemented fiber channel technology. These enterprises usually demand established technology, need high bandwidth storage solutions and are ready to invest in the hardware needed to meet their reliability and performance requirements, and typically have full time personnel devoted to storage-management.
Many of these data centers keep investing in fiber channel storage solutions and plan to continue investing in the foreseeable future. Fiber channel technology was presented to the market at one gigabit per second in 1997 and has doubled in speed every three or four years.
Generally speaking fiber channel is backward friendly with the two previous generations this means that 32 Gigabit fiber channel switches, optics and Host Bus Adapters (HBAs) are backward compatible with 16 Gigabit and 8 Gigabit equipment.
When using fiber channel there are three fundamental methods to connect servers known as initiators to storage which are called targets. These are Direct Connect, Arbitrated leaf, and switched fabric. Switched fabric is the most famously deployed while arbitrated-loop is becoming less famous.
Fiber Channel Host Bus Adapters referred to as HBAs connect devices to the fiber channel network or another fiber channel device. Fiber channel storage-arrays can be formed of hard disk drives, solid-state drives or a mixture of the two.
Fiber channel switches are used to direct traffic into a fiber channel fabric. Backbones or directors form the core of an enterprise fiber channel fabric and edge-switches are the local attach-points into the fabric. Enterprise fiber channel fabrics often have redundant mechanisms to provide high-availability.