The original SAN was not always Storage Area Network. SAN had a twin nomenclature called System Area Network (SAN) back in the late 90s. Fibre Channel fabric topology (THE Storage Area Network) was only starting to take off when many of the Fibre Channel topologies at the time were either FC-AL (Fibre Channel Arbitrated Loop) or Point-to-Point. So, for a while SAN was System Area Network, or at least that was what Microsoft® wanted it to be. That SAN obviously did not take off.
System Area Network (architecture shown below) presented a high speed network where server clusters can communicate. The communication protocol of choice was VIA (Virtual Interface Adapter), and the proposed applications, notably the Microsoft® SQL Server, would use Winsock API to interface with the network services. Cache coherency in the combined memory resources of a clustered network is often the technology to ensure data synchronization, consistency and integrity.
Alas, System Area Network did not truly take off, and now it is pretty much deprecated from the Microsoft® universe.
System Area Network (SAN)
