In a previous discussion on this list, I was advised grub does not boot over NFS, and that it must use TFTP only.
I had asked the questionn because of this article [
http://www.wonkity.com/~wblock/docs/html/pxe.html) where it states:
gpxelinux.0 from the SYSLINUX project will be used as a PXE boot loader
XUbuntu With NFS: This menu entry sets the netboot and nfsroot options.
"label xubuntu \ menu label XUbuntu \ kernel images/xubuntu/casper/vmlinuz \ append boot=casper netboot=nfs \ nfsroot=192.168.1.1:/usr/tftpboot/images/xubuntu \ initrd images/xubuntu/casper/initrd.lz"
I just wanted to advise that, although I have not tried it, SysLinux seems able to boot over NFS. I hope one day Grub will be able to as well.
Thanks and Regards.