The SAN File System cluster is a set of metadata servers, each running on a separate hardware engine. The metadata servers communicate with each other and with SAN File System clients over your existing IP network. The cluster provides a single point of control for administrative and service operations.
The cluster has one master metadata server, which is initially designated by an administrator, and one or more subordinate metadata servers. The master metadata server maintains the cluster state and is the focal point for most administrative services. The maximum number of metadata servers that SAN File System allows in the cluster is eight.