NFSv4 is available in FreeBSD 9.0 and later. nfsuserd is a daemon that maps the number of uid/gid from users and groups. FYI, Man page http://www.freebsd.org/cgi/man.cgi?query=nfsuserd&apropos=0&sektion=0&manpath=FreeBSD+9.2-RELEASE&arch=default&format=html rc.d script. http://svnweb.freebsd.org/base/release/9.1.0/etc/rc.d/nfsuserd?revision=243808& view=markup
Created attachment 359880 [details, diff] sample patch for freebsd-usbin-9.2_rc3.ebuild nfsuserd.initd and nfsuserd.confd are available from gentoo-bsd overlay. http://git.overlays.gentoo.org/gitweb/?p=proj/gentoo-bsd.git;a=blob_plain;f=sys-freebsd/freebsd-usbin/files/nfsuserd.initd;hb=HEAD http://git.overlays.gentoo.org/gitweb/?p=proj/gentoo-bsd.git;a=blob_plain;f=sys-freebsd/freebsd-usbin/files/nfsuserd.confd;hb=HEAD
freebsd-usbin-9.1 is too old. Please use the newer version. closing.