Hi!
Quote Originally Posted by knp View Post
... the fixed HDD already contains a SOS_knoppix partition.
...knp
Your project is not at all problematic! It's easy to solve.
That SOS HDD will create problems if it has knoppix iso or persistent.
Remove any Knoppix persistent and image that might be in the HDD. I have a 'solved' post which has knoppix ISO, persistent and grub to boot knoppix from USB flashdrive.
Afterwards, you can add connect your HDD and enjoy its huge data storing ability. If you format it to ext4 you could direct knoppix to use it as a persistent itself.
My posts has all the guidelines, if you can connect the dots.
And why did you say COMPLEMENTS? I know you have a problem with English, but I also know you use online Google Translation for brushing up your post.