There is virtualization and clustering. When the server needs access to one disk space, such data storage systems are generally indispensable. Technologically, SAN consists of the components: nodes, network infrastructures, switches, routers in complex and distributed networks.

For SANs, the key parameters are not only performance, but also reliability. After all, if the database server loses its network for a couple of seconds (or even minutes) – it can lead to downtime and decrease the general performance of the company. 

And if the hard disk with the base or with the OS falls off at the same time, the effect will be much more serious. Therefore, all SAN components are usually duplicated – ports in storage devices and servers, switches, links between switches and, a key feature of SAN, compared to LAN – duplication at the level of the entire infrastructure of network devices – factories.