init.d scripts for shutdown and reboot

[Kailesh Mussai]

Dear all,

I am trying to understand how ubuntu does a shutdown.  From what I
understand in the rc0.d, here is a part of ls -l:

root at turkana:/etc/rc0.d# ls -l

lrwxrwxrwx 1 root root  13 2008-10-10 11:45 K01gdm -> ../init.d/gdm
---snip----
lrwxrwxrwx 1 root root  22 2008-10-10 11:45 S31umountnfs.sh -> ../init.d/umountnfs.sh
lrwxrwxrwx 1 root root  17 2008-10-14 10:30 S32portmap -> ../init.d/portmap
lrwxrwxrwx 1 root root  20 2008-10-10 11:45 S35networking -> ../init.d/networking
lrwxrwxrwx 1 root root  18 2008-10-10 11:45 S40umountfs -> ../init.d/umountfs
lrwxrwxrwx 1 root root  20 2008-10-10 11:45 S60umountroot -> ../init.d/umountroot
lrwxrwxrwx 1 root root  14 2008-10-10 11:45 S90halt -> ../init.d/halt

The init scripts umountnfs.sh, umountfs, umountroot do nothing when
started but only when stopped, an example is:

root at turkana:/etc/rc0.d# /etc/init.d/umountfs start # No-op

The reason I am asking is, I have network boot hosts which uses there
own local disk with aufs and having trouble umounting those local
mounts.

I'll appreciate any help, if I am unclear, please let me know.

Best regards,
Kailesh