I also use rdfile and wrfile a lot from vfiler0. Not officially supported, but an easy way to edit if getting host access isn't easy or if you only have console access. And then backup with snapshots or mv commands. Hopefully we get a gui some day into this...it isn't in the beta of nsm 2.0 so hopefully 2.0.1 or 2.1 adds gui management of vfilers (hint hint to any product managers reading this ).
priv set advanced
rdfile /vol/vfiler1_root/etc/exports # copy the contents
mv /vol/vfiler1_root/etc/exports /vol/vfiler1_root/etc/exports.ccyymmdd # backup.. and/or "snap create"
Edit the file in vi or wordpad..
wrfile /vol/vfiler1_root/etc/exports # paste and ctrl-c when done