# create export in memory and write to /etc/exports (use specific options)
exportsfs -io sec=sys,rw,anon=0,nosuid /vol/vol0

source: http://www.datadisk.co.uk/html_docs/netapp/netapp_file_access.htm

the following command re-reads changed file and executes changes
example: source -v /etc/rc

good NetApp resource: http://www.wafl.co.uk/