>  What is single-user mode, why, and how?
>
>          'single-user' mode is when the kernel has booted, but only runs
>          a single shell on the console. If you boot single user only the
>          root filesystem will be mounted, and it will be mounted
>          read-only. Among the many uses for single-user mode are:

I think it'd be worthwhile to mention explicitely that the root
filesystem is mounted read-only, not writable before "mount -u
/dev/XXX /" is done.  (If /kern is available all the time, "mount -u
/kern/rootdev /" is a better way)

Tohru Nishimura