Patrick Bégou :
About NFS home directories and CentOS have you .nfsxxxxxxxxx tempory files located in the home of your user ? I have this very often. I was not able to found any documentation about this but if they are temporary files for NFS transactions is there a way to store them on on local client disk area like /tmp instead of a NFS storage? These files are some time difficult (if not impossible) to remove by the user on the client side and stay on the disk... until I remove the oldest ones on the server side.
Have a look at the (original) Linux NFS FAQ:
http://nfs.sourceforge.net/#section_d
James Pearson