Nache: Design and Implementation of a Caching Proxy for NFSv4

In this paper, we present Nache, a caching proxy for NFSv4 that enables a consistent cache of a remote NFS server to be maintained and shared across multiple local NFS clients. Nache leverages the features of NFSv4 to improve the performance of file accesses in a widearea distributed setting by bringing the data closer to the client. Conceptually, Nache acts as an NFS server to the local clients and as an NFS client to the remote server. To provide cache consistency, Nache exploits the read and write delegations support in NFSv4. Nache enables the cache and the delegation to be shared among a set of local clients, thereby reducing conflicts and improving performance. We have implemented Nache in the Linux 2.6 kernel. Using Filebench workloads and other benchmarks, we present the evaluation of Nache and show that it can reduce the NFS operations at the server by 10-50%.