Issues in the design of multi-server file systems to cope with load skew

It is observed that a large number of operations in many environments are to the files that are mostly-read and rarely updated. Such operations can be served by any server without incurring a high coherency. Several dynamic load balancing algorithms of various degrees of complexity that achieve high reduction in load skew albeit reducing the server buffer hit probability are proposed. It is shown using real workload traces that server load skew can be significantly reduced using these policies, and that there is an inherent tradeoff between load balancing and server buffer hit probability. Some variations of the proposed buddy-based policies which limit the number of replications of buffer pages seem to provide a good compromise between the two factors