Microsoft® SQL Server 2012 Unleashed

What Is a SAN?

A SAN contains multiple high-performance hard drives coupled with high-performance caching controllers. The hard drives are often configured into various RAID configurations. These drive configurations are virtualized so that the consumer does not know which hard drives a SQL Server or other device connected to the SAN will access. Essentially, the SAN presents blocks of storage to servers that can consist of a single hard drive, multiple hard drives, or portions of hard drives in a logical unit called a logical unit number (LUN). Connection to a SAN is typically through Fibre Channel, a high-speed optical network.

SANS can provide advantages over locally attached storage. Most SANs provide features that allow you to clone, snapshot, ...