I tried to set up one of my debian based servers to allow network booting of some diskless PCs. When doing this, I got the nfs-kernel-server package replaced by nfs-user-server. I don’t know why, may be that I folloved Adam Pierces’ instructions too closely.
It ended up that the first test box booted nicely of the network, but for some reason refused to mount the root volume. No possibilites to get any information out of the box, except the obivious, that it did not work. (maybe I had not enough patience to wait for the root mount time out so that I could get into the busybox-shell). Well, after a while, I tried to mount the root volume on another machine, and lo and behold, I was refused access.. and on closer inspection I could not access any other nfs volumes of that server either. So, get out the nfs-user-server and get the nfs-kernel-server back and running and I got one step further. Still has to do some serious work on the initrd image to get all the drivers I need to work, but got past one hurdle..