Allow vagrant to update the nfs export without password
If you want to allow vagrant to change the nfs export without entering an password you can add this to your sudoers file (to edit it just type visudo as root):
# Allow passwordless startup of Vagrant when using NFS.
Cmnd_Alias VAGRANT_EXPORTS_ADD = /usr/bin/su root -c echo ‘*’ >> /etc/exports
Cmnd_Alias VAGRANT_NFSD = /sbin/nfsd restart
Cmnd_Alias VAGRANT_EXPORTS_REMOVE = /usr/bin/sed -e /*/ d -ibak /etc/exports
%staff ALL=(root) NOPASSWD: VAGRANT_EXPORTS_ADD, VAGRANT_NFSD, VAGRANT_EXPORTS_REMOVE