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Storage Area Network

SAN

A dedicated high-speed network providing block-level storage access between servers and storage arrays, appearing to servers as locally attached disks — used for databases, virtualised workloads, and mission-critical applications.

Unit: IOPS / GB/s / TB capacity

Full Definition

A Storage Area Network (SAN) is a specialised network connecting servers to storage arrays at the block level. To the server operating system, SAN-attached storage appears as a local disk — the server manages the filesystem; the SAN provides raw block storage. This contrasts with NAS (file-level access) and object storage (API/HTTP access).

Two primary SAN transports are used in datacentres: Fibre Channel (FC) SANs, using dedicated FC switches and HBA adapters at 16 or 32 Gb/s — the traditional enterprise SAN fabric; and iSCSI SANs, which encapsulate SCSI commands over standard IP networks at lower cost.

SANs are used for VMware and Hyper-V datastores (shared block storage enabling VM live migration), Oracle and SQL Server databases, and other applications requiring high IOPS with consistent latency. All-flash SANs from NetApp, Pure Storage, and Dell EMC are the current standard for performance-sensitive enterprise workloads.

Also Known As

Fibre Channel SANiSCSI SANblock storage

Source Reference

SNIA (Storage Networking Industry Association) Storage Networking Dictionary; FC-SAN Architecture Reference

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