samba mount failed with "CIFS VFS: cifs_mount failed w/return code = -6" and "is not a valid block device"
Environment: server: Windows client: RHEL 6.7 (samba-common-3.6.23-20.el6.x86_64) or Debian Wheezy (samba-common-bin 2:3.6.6-6+deb7u7) Client's /etc/...