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 le system support to mobile users through optimistic caching at the mobile client. Tradeoos between resources and performance are explored across a variety of design choices, speciically issues relating to system connguration, policies for le system updates (write backs), and choice of caching unit (whole-le caching or block-based caching). The results of our experiments show that it is possible to provide quite acceptable remote le service to weakly connected mobile clients, even when 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.

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