An interesting question is the applicability of our results to other protocols such as NFS v4, DAFS, and SMB.
The SMB protocol is similar to NFS v4 in that both provide support for strong consistency. Consistency is ensured in SMB by the use of opportunistic locks or oplocks which allow clients to have exclusive access over a file object. The DAFS protocol specification is based on NFS v4 with additional extensions for hardware-accelerated performance, locking and failover. These extensions do not affect the basic protocol exchanges that we observed in our performance analysis.
NFS v4, DAFS and SMB do not allow a client to update meta-data asynchronously. NFS v4 and DAFS allow the use of compound RPCs to aggregate related meta-data requests and reduce network traffic. This can improve performance in meta-data intensive benchmarks such as PostMark. However, it is not possible to speculate on the actual performance benefits, since it depends on the degree of compounding.