Distributed systems can be built to a client-server model in which one of the important servers is the file server, consisting of at least one processor and disk drive, attached to the network with the sole purpose of storing information on behalf of its clients. In the Department of Computing at Lancaster University a file server which is connected to both of their networks has been designed and built: an Ethernet-type network (called Strathnet, of local design) and a Cambridge Ring type network. The Arca File Server is based on work started at Cambridge University. This paper describes the background of file servers for local networks and the design and implementation of the system.