In computer networking, a virtual storage area network (VSAN) is a collection of ports from a set of connected Fibre Channel switches, that form a virtual fabric. Ports within a single switch can be partitioned into multiple VSANs, despite sharing hardware resources. Conversely, multiple switches can join a number of ports to form a single VSAN.
Cisco Systems designed VSANs modelled after the virtual local area network (VLAN) concept in Ethernet networking, but applying the idea to a storage area network. In October 2004 the Technical Committee T11 of the International Committee for Information Technology Standards approved VSAN technology as a standard of the American National Standards Institute (ANSI).
A VSAN, like each Fibre Channel (FC) fabric, can offer different high-level protocols such as FCP, FCIP, FICON, iSCSI. Each VSAN is a separate self-contained fabric using distinctive security policies, zones, events, memberships, and name services. Traffic is also separate.
Unlike a typical fabric that is resized switch-by-switch, a VSAN can be resized port-by-port.
The use of VSANs allows the isolation of traffic within specific portions of the network. If a problem occurs in one VSAN, that problem can be handled with a minimum of disruption to the rest of the network. VSANs can also be configured separately and independently.