A Protocol for Lock Based Cache Consistency in the Pegasus File System

We describe a system for caching of files in a distributed file system where a locking protocol is used as the mechanism for maintaining consistency. The design of a protocol and the design and implementation of a caching file system will be given. The cost of this protocol is shown and we conclude that a caching file system can be kept consistent efficiently by using the locking protocol. UNIX is a registered trademark of UNIX Systems International SUN is a registered trademark of SUN Microsystems Inc. NFS is a registered trademark of SUN Microsystems Inc. III IV Preface This report is written as my master thesis for the degree sivilingenir at the University of Troms, Norway. My supervisor in Troms has been Dag Johansen. All the work in this report has been done at the University of Twente, The Netherlands where my supervisor has been professor Sape Mullender. I wish to thank all people at both the University of Troms and the University of Twente. I send a special thanks to all the people at the Pegasus project at the University of Twente which has inspired the work with this report. I am especially thankful to Arne Helme, Tage Stabell-Kul, Alberto Bartoli, Peter Bosch, Gianluca Dini and Martijn van den Valk. We have had a lot of interesting discussions and I have learned very much working with them. In Troms I want to thank Svenn A. Hanssen for being a good friend and fellow student in these years. He have had many long discussions about virtually everything interesting. I will thank Arne Helme and Tage Stabell-Kul for reading drafts of this report and providing many constructive suggestions. Arne has also helped me with L a T E X. And I would like to thank professor Sape Mullender for creating a very interesting environment to work in. Most of the ideas which this re..