You can define NFS parameters in the /etc/system file, which is read during the boot process. Each parameter includes the name of its associated kernel module. For more information, see Tuning an Oracle Solaris System.
Caution - The names of the parameters, the modules that they reside in, and the default values can change between releases. Check the documentation for the version of the active SunOS release before making changes or applying values from previous releases.