[OpenAFS] problem configuring top level of afs filespace

[yam]

I'm gone through the quick install guide, here are my problems:

First, I have skipped the client installation part.. Is it needed to give
that machine only server funcionality? I mean, do I have to install client
part, and then uninstall it??

Besides that, when I'm about to start configuring the Top Level afs
filespace, I issue the following command:

# /usr/afs/bin/fs setacl /afs system:anyuser rl
fs: Invalid argument; it is possible that /afs is not in AFS.

Where the wrong point?

Tnx in advance.