I just talked to H.J. Lu (current maintainer of knfs) and he confirmed that knfsd can't do the following things: - export all the filesystems as if there were only one by exporting / - export nfs mounted filesystems (actually, I forgot to ask that one, but it doesn't seem to work) - handle a client reading a file that is moved on the server outside of the directory where it was when it was open (that's because the filehandle depends on dentries) #1 is a big issue when you use autofs since if you want to allow /hosts/machine automounts, all the servers have to export the same filesystem and you put a * &:/ entry in your auto.hosts map. This will fixed once autofs can recursively mount sub-mountpoints on servers, but until then, user level nfs is the way to go. My point is that knfs is cool, but it's not yet a once size fits all solution, and there are good reasons to still run the user level version, so I think RH should provide both.
Providing both will be a soirce of confusion for a lot of people. For all the problms described there are workarounds available, that while inconvenient will solve the problems. user level nfsd is no longer being maintained, and the sooner we cut the cord the better.