nfsstat can be used to examine NFS performance.
nfsstat -s reports server-side statistics. In particular, the following are important: calls : Total RPC calls received. badcalls : Total number of calls rejected by the RPC layer. nullrecv : Number of times an RPC call was not available even though it was believed to have been received. badlen : Number of RPC calls with a length shorter than that allowed for RPC calls. xdrcall : Number of RPC calls whose header could not be decoded by XDR (External Data Representation). readlink : Number of times a symbolic link was read. getattr : Number of attribute requests. null : Null calls are made by the automounter when looking for a server for a filesystem. writes : Data written to an exported filesystem. Sun recommends the following tuning actions for some common conditions: writes > 10% : Write caching (either array-based or host-based, such as a Prestoserv card) would speed up operation. badcalls >> 0 : The network may be overloaded and should be ch...