Book excerpt: This book was originally published in 1995. At the time of publication, distributed file systems were monolithic and only supported single file abstractions. Network storage devices needed to be able to accommodate emerging information media such as digital audio and video, with data radically different in characteristics to traditional text and binary that file systems were optimised for. By combining emerging and traditional media, information could be recorded and presented in the most suitable way, and the value of a piece of information could be further enhanced by linking together related pieces. However composite data and cross-reference between data items raised a number of system issues that had not been addressed properly before. In this book Dr Lo defined a multi-service storage architecture that could meet the needs of existing and emerging applications and support multiple file abstractions. He also explored a number of related design issues.