Storage area network
A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block-level data storage. SANs are primarily used to access data storage devices, such as disk arrays and tape libraries from servers so that the devices appear to the operating system as direct-attached storage. A SAN typically is a dedicated network of storage devices not accessible through the local area network (LAN).
| Computer network types by scale |
|---|
| Fibre Channel | |
|---|---|
| Layer 4. Protocol mapping | |
| LUN masking | |
| Layer 3. Common services | |
| Layer 2. Network | |
| Fibre Channel fabric Fibre Channel zoning Registered state change notification | |
| Layer 1. Data link | |
| Fibre Channel 8b/10b encoding | |
| Layer 0. Physical |
Although a SAN provides only block-level access, file systems built on top of SANs do provide file-level access and are known as shared-disk file systems.
Newer SAN configurations enable hybrid SAN and allow traditional block storage that appears as local storage but also object storage for web services through APIs.