A Storage Area Network (SAN) is a specialized network infrastructure that connects multiple servers with shared storage devices such as disk arrays, tape libraries, and solid-state storage. Unlike Network Attached Storage (NAS), which is file-based, SAN provides block-level access to storage, delivering higher performance and flexibility.
Architecture and Technology
SAN uses specialized communication protocols such as Fibre Channel or iSCSI to connect servers to storage. Fibre Channel is a dedicated protocol with high throughput (10 Gbps to 128 Gbps) commonly used in enterprise data centers. iSCSI encapsulates SCSI commands within the TCP/IP protocol, enabling it to leverage standard Ethernet networks, which are more cost-effective.
Enterprise Benefits
SAN separates storage from computation — a single storage array can be shared by dozens of servers, improving resource efficiency and ease of management. Servers can failover to other servers in a cluster since they all see the same disks, facilitating high availability. Backups and snapshots can also be performed at the storage level without consuming server bandwidth.
Complexity and Cost
Setting up a SAN requires specialized technical expertise and significant hardware investment. Storage performance tuning, snapshot management, and disaster recovery also require careful planning to avoid bottlenecks.