Quote Originally Posted by utu View Post
I have two concerns with the initial premise here.

Unless your Knoppix user is denied root privileges,
making that partition which contains /mnt-system read-only on a write-able
medium offers no real protection against unauthorized changes to the contents
of /mnt-system.

If the Knoppix user is denied root privileges completely,
there are many useful things his Knoppix can't do.

I'd like to see how changes to init might get around these considerations.
Even if it is possible to remount /mnt-system rw, having it mounted ro by default is clearly a safety measure. And, for example, everything could be placed in loop-mounted ISO images. So that you have to re-create it each time you want to update your persistent store. This could be equivalent to using one or more cloop/squashfs overlays.