Potential benefits of file migration in a heterogeneous distributed file system

Due to limited numbers of resources in a distributed system, resource management strategies such as file migration have become increasingly important. We establish through simulation, that in a heterogeneous environment, a system which migrates whole files from congested to less congested storage sites can result in significant performance gains over a system without file migration. Our file migration policy is based on an instantaneous performance gain analysis; basically, a file migration is performed whenever if seems to lower the total response time of requests already in the system. User behavior in our system is modeled with time-varying file request probabilities in order to create variable levels of file access intensities. Our model establishes the conditions under which file migration is beneficial in a heterogeneous distributed file system