Comment 4 for bug 872376

continuing my assumptions, this looks like the same outcome:

"""
NFSv4 requires that all filenames be exchanged using UTF-8 over the wire. The NFSv4 specification, RFC 3530, says that filenames should be UTF-8 encoded in section 1.4.3: "In a slight departure, file and directory names are encoded with UTF-8 to deal with the basics of internationalization." The same text is also found in the newer NFS 4.1 RFC (RFC 5661) section 1.7.3. The current Linux NFS client simply passes filenames straight through, without any conversion from the current locale to and from UTF-8. Using non-UTF-8 filenames could be a real problem on a system using a remote NFSv4 system; any NFS server that follows the NFS specification is supposed to reject non-UTF-8 filenames. So if you want to ensure that your files can actually be stored from a Linux client to an NFS server, you must currently use UTF-8 filenames. In other words, although some people think that Linux doesn't force a particular character encoding on filenames, in practice it already requires UTF-8 encoding for filenames in certain cases.
"
http://lwn.net/Articles/71472/ "The kernel and character set encodings"