Cluster filesystem – a distributed filesystem that is not a single server with a set of clients, but instead a cluster of servers that all work together to provide high performance service to their clients. To the clients the cluster is transparent – it is just “the filesystem”, but the filesystem software deals with distributing requests to elements of the storage cluster.
Xsan is a 64-bit cluster file system that provides concurrent data access over high- speed Fibre Channel to multiple systems on the network. For better performance and higher availability, you can pool storage across multiple RAID devices, and each
Xsan client can use this centralized data as if it were directly connected. Cluster file systems of this class include SGI Infinite Storage Filesystem CXFS and VERITAS Storage Foundation Cluster File System.