Knoppix won't let me access USB it's running from

[omni_engineer]

So I got this giant 16 GB flash drive in a black friday sale. Since I don't have that much RAM, I figured I would store all my application data and such on the persistance image which takes up 2GB, and the other 14GB would be used for large files (music, video, ect.) I used this idea in Puppy Linux, and the space freed up in the persistance image really helped during boots. When I switched to Knoppix (BEST OS EVER!!!), I can't find the USB it's running from. I think it's mounted in the "mnt-system" file, but it says "permission denied" when I try to open it, even though I'm administrator. WTF! (F stands for fudge)

[Werner P. Schulz]

When I switched to Knoppix ..

What do you mean by this?

Make a flash disk installation of Knoppix to the 16 GB USB and create persistent memory (1 -4 GB)
Boot the Knoppix
Within a terminal type

cd /
df -h

You can see "used/ free" space at '/mnt-system/'. The free space at '/mnt-system/' you can use to store other files like music.

[omni_engineer]

Never mind, I solved it my booting another linux distro, and changed the permission on my USB