What to kill with confidence when it comes to the NFS mount option?

Question

In the following link

http://www.faqs.org/docs/Linux-HOWTO/NFS-HOWTO.html

He said the process isn’t killing, other than "sure killing", but what kind of murder?

hard (option to connect an NFS client)

A program accessing a file in an NFS mounted file system will freeze when a server crashes. This process cannot be interrupted or killed ( except for "sure kill" ), unless you also specify intr. When the NFS server back on the Internet, the program continues unperturbed from where it was. We recommend using hard, intr on all NFS mounted file systems.

Answer 1

I think this means kill -9, although please note that you have been reading a rather old manual (like most other TLDP methods, I think) since 2002, and with respect to the NFS mount options are hard,intralready installed by default and

The mount option intr / nointr is deprecated after the 2.6.25 kernel. Only SIGKILL can interrupt pending NFS operation on these cores, and if this mount parameter is specified, it is ignored to ensure backward compatibility with older cores.