When I ran the unix command “ls -la”, a .nfsXXXXXX file showed up…this was created as a temporary file when an open file was deleted on NFS mounted file systems. The file is created so the unfinished process can continue writing/reading to that file which was deleted. It stays around even after the process has finished.

Thanks to the University of S. Wales’ Engineering Dept.’s Deleting .nfs files article.