Quote Originally Posted by jackren
When do I need to use initrd?
You only need initrd if the file system for the partition where knoppix is installed is compiled as a module. Check your .config file if the line for the file system is "m" for example "reiserfs=m". If it is " reiserfs=y" then you don't need initrd.

I recommend that you compile with the fs into the kernel(filesystem=y) as I have done this many times before. Creating the initrd file is a bit difficult.