Browse Prior Art Database

WFS: A Simple Shared File System for a Distributed Environment

IP.com Disclosure Number: IPCOM000128885D
Original Publication Date: 1979-Dec-31
Included in the Prior Art Database: 2005-Sep-20
Document File: 11 page(s) / 42K

Publishing Venue

Software Patent Institute

Related People

Daniel Swinehart: AUTHOR [+5]

Abstract

Fxisting file systems implement different levels of service for their clients, and correspondingly leave different amounts of work for the clients to do. Traditionally, file systems have evolved to provide more and more functionality from simple file access to complicated arrangements which provide sharing, security, and distributed data storage.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

WFS: A Simple Shared File System for a Distributed Environment

by Daniel Swinehart, Gene McDaniel, and David Boggs

CSL-79-13 October 1979

Abstract: WFS is a shared file server available to a large network community. wFs responds to a carefully limited repertoire of commands transmited through a network by client programs, and can be viewed as a remote intellegent disk controller. The system does not utilize network connections, but instead services independent page-level requests, one per per packet. The design emphasizes reliance upon client programs to implement the traditional facilities (stream i/o, a directory system, etc,.) of a file system. The use of atomic file commands and connectionless network protocols nearly eliminates the need for WFs to maintain state information from request to request. Various uses of the system are discussed and extensions are proposed to provide security and protection without violating the design principles.

A version of this paper will appear in Operating Systems Review, vol. 13 no. 5, Nov. 1979,

Key words and phrases: file systems, computer networks

XEROX PALO ALTO RESEARCH CENTER

3333 Coyote Hill Road / Palo Alto / California 94304 WFS: A Simple Shared File System for a Distributed Environment 1

1. Introduction

Fxisting file systems implement different levels of service for their clients, and correspondingly leave different amounts of work for the clients to do. Traditionally, file systems have evolved to provide more and more functionality from simple file access to complicated arrangements which provide sharing, security, and distributed data storage.

This paper describes WFS, a file system that provides a concise set of file operations for use in a distributed computing environment. Designed by the authors in 1975, and built by one of us (Boggs) in under two months, WFS has successfully supported a number of interactive applications. The filing needs of Woodstock, an early office system prototype, dictated the functional and performance criteria of wFs. Woodstock provided facilities for creating, filing, and retrieving simple office documents, and a rudimentary facility for exchanging these documents as electronic messages.

Woodstock's hardware environment was a network of minicomputers, each providing specialized functions (terminal control, editing, filing, message services, etc.) in support of the overall application. WIFS was designed as the shared filing component, storing Woodstock documents on high-capacity disks attached to one of these processors. During development, Woodstock used small local disks on each editing processor. The software that supported the editing application provided the facilities for transforming access to physical disk pages into higher-level functions. These included character and word i/o, file positioning, and functions for opening and closing files. The application also implemented its own...