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.
VSANs were designed by Cisco, modelled after the virtual local area network (VLAN) concept in Ethernet networking. In October 2004, the Technical Committee T11 approved VSAN technology into the American National Standards Institute (ANSI) as the standard.
A VSAN, like each 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 traffic to be isolated 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.