Distributed management of replicated and partitioned files under DRAGON SLAYER

The authors describe the file management system of DRAGON SLAYER, a distributed operating system which provides transparent resource sharing in a heterogeneous local area network with completely decentralized control. Users are able to use any of the system files for which they have authorization, without regard to the individual characteristics of the computers on which the files reside or the physical locations of the users and files. In addition, files can be dynamically fragmented, and the fragments can be replicated and relocated dynamically. Copies are kept mutually consistent while all file operations work either transparently on the whole file or on specific fragments. The DRAGON SLAYER resource management supporting these file system operations is presented. Beyond the obvious advantages of file access reliability and flexibility, the authors present simulation results proving the superior performance of this file system as compared with conventional distributed file systems with non-fragmented files