File migration and file replication: a symbiotic relationship

Much of the past research on file migration and file replication has examined these two resource management strategies in isolation or in an environment where they do not work together. We establish through simulation that these two strategies can be utilized simultaneously to potentially provide significant performance benefits over a system without file migration or replication. File replication can be viewed as a natural extension to file migration, and thus, we derive a dynamic file replication policy based on an established file migration heuristic: a file is migrated (or replicated) whenever a reduction in total mean response time of the file requests currently in the affected storage sites can be achieved. Through our performance model, we use simulation to establish the conditions under which our file migration/replication policies are beneficial in a distributed file system.