Cache Management for Mobile File Service

File service is a fundamental computing requirement, but one that has been problematic for mobile users. Concerns about the latency associated with transferring large amounts of data over network connections of unknown quality have led to rather ad hoc approaches that provide some functionality, but with uncertain performance. Through a series of trace-driven simulation experiments, we investigate performance issues relating to providing remote file system support to mobile users through optimistic caching at the mobile client. Trade-offs between resources and performance are explored across a variety of design choices, specifically issues relating to the system configuration, policies for file system updates (write backs), and the choice of caching unit (whole-file caching or block-based caching). The results of our experiments show that it is possible to provide quite acceptable remote file service to weakly connected mobile clients, even when the bandwidth is limited. Reads can be serviced in a timely manner, updates can be committed in an acceptable period of time and resource requirements at the client are modest.