A distributed data storage system stores a single image file system across a plurality of physical storage volumes. The physical storage may be direct attached storage, or may be coupled through a storage area network (“SAN”). One or more clients communicate with a plurality of storage nodes through a network. A client of the distributed data storage system transmits a request over the network for a file identified in the file system. A load-balancing switch selects one of the storage nodes to process the request. The storage node accesses at least one of the physical volumes and transmits a response for the storage operation to the client.