NFS Tricks and Benchmarking Traps

We describe two modifications to the FreeBSD 4.6 NFS server to increase read throughput by improving the read-ahead heuristic to deal with reordered requests and stride access patterns. We show that for some stride access patterns, our new heuristics improve end-to-end NFS throughput by nearly a factor of two. We also show that benchmarking and experimenting with changes to an NFS server can be a subtle and challenging task, and that it is often difficult to distinguish the impact of a new algorithm or heuristic from the quirks of the underlying software and hardware with which they interact. We discuss these quirks and their potential effects.

• Type: Conference
• Year: 2003
• Where: USENIX
• Authors: Daniel Ellard, Margo I. Seltzer
• Keywords: Freebsd 4.6 Nfs, NFS Server, Operating System, Stride Access Patterns, USENIX 2003