You can use nfsstat to display or reset counts of calls made to Server for NFS.
Syntax
nfsstat [-z]
Description
When used without the -z option, the nfsstat command-line utility displays the number of NFS V2, NFS V3, and Mount V3 calls made to the server since the counters were set to 0, either when the service started or when the counters were reset using nfsstat -z.