This is my understanding, not by reading kernel source.

In message <17832.945651410@coconut.itojun.org>
	on Mon, 20 Dec 1999 09:56:50 +0900,
	itojun@iijlab.net wrote:
> 	- make sure in single user mode, no update(8) running
When the system booted in single user mode, the root filesystem mounted
as read-only.  So after fsck(8), we could simply reboot.

When the system went into single user mode from multi user mode, the
root filesystem mounted as read-write.  So after unmounting all file
systems (after stop accounting), re-mount the root file system
read-only.

	# mount -u -o ro /

And after fsck(8), we could simply reboot.


But when I enabled soft dependency in the root filesystem, I need to the 
process bellow.

1. Go into single user mode.
2. Remount the root filesystem read-only.
3. Enable soft dependency with tunefs(8).
4. Restart the system with reboot(8) using "-n" and "-q" option.

It might not need to both "-n" and "-q" option.

Since these are my experience, something might be wrong.

Cheers.

--
Takahiro Kambe <taca@sky.yamashina.kyoto.jp>