title: what's "sure kill" when talking about NFS mount option?
body: <p>In the following link</p>
  
  <p><a href="http://www.faqs.org/docs/Linux-HOWTO/NFS-HOWTO.html" rel="nofollow noreferrer">http://www.faqs.org/docs/Linux-HOWTO/NFS-HOWTO.html</a></p>
  
  <p>It said a process is not killable except by a "sure kill", but what's sure kill?</p>
  
  <blockquote>
    <p>hard (NFS client mount option)</p>
    
    <p>The program accessing a file on a NFS
    mounted file system will hang when the
    server  crashes. The process cannot be
    interrupted or killed (<strong>except by a
    "sure kill"</strong>) unless you  also
    specify intr. When the NFS server is
    back online the program will continue
    undisturbed  from where it was. We
    recommend using hard,intr on all NFS
    mounted file systems.</p>
  </blockquote>