NFSv4 lets you route all your NFS traffic through a single, well-known TCP port (2049). Horray, it really works, it really gets rid of one of the stupidities in previous versions of NFS. It lets you use firewalls again.
NFSv4 maps every user on the client to 4294967294. In order to do user name translation it requires Kerberos. (Forget about keeping fixed UIDs like in the good old days — that doesn’t seem to work at all). Great for setting up an Enterprise(TM) service with 1000 clients. Absolutely fucking useless to just share a filesystem between two machines.
There’s a serious point to this rant.
When you’re designing a system that you want people to use, make the easy cases easy.
Don’t make me read through a dozen obscure man pages and half a dozen really obscure configuration files to just have the basic function working.
NFSv4 has so far been a 100% failure for me and for many many other people because no one thought about making the easy case easy.