Usb boot knoppix

[jena]

Hello!!!
I'm trying to boot 2 live distribution backtrack 3 e knoppix 5.1.1 on a usb drive...
I made the first partition for boot loader grub that point to 2 other partition where are the 2 live...
I copied the knoppix's files by mounting the cd iso and copying the content on the pen drive...
The problem is what knoppix after loading the kernel starts hardware detection and i receive an error...
Accessing KNOPPIX cd at /dev/sda3...
Found primary KNOPPIX compressed image at /cdrom/KNOPPIX./KNOPPIX/bin/ln: cannot remove '/sbin':read only file system
/linuxrc: cannot create /etc/ld.so.cache: read only file system

When knoppix have to detect the usb device these run from sda to sdz and i receive an error:

Can't find KNOPPIX filesystem, sorry.
Dropping you to a (very limited) shell.
Press reset button to quit.

This is the part of menu.lst of grub about knoppix:

title Knoppix 5.1.1
root (hd0,2)
kernel /boot/isolinux/linux root=/dev/ram0 init=/etc/init lang=it apm=power-off vga=791 nomce quiet BOOT_IMAGE=knoppix ro quiet splash
initrd /boot/isolinux/minirt.gz
quiet

I don't understand what's the error...
I hope you can help me...
Thank you!!!

[hat_monkey]

On this forum there details for grub booting the .iso without having to unpack it. Try that. Other than that try putting the files in a directory closer to root. Eg. /linux

[jena]

Hello!!!
The solution is herea http://www.knoppix.net/wiki/USB_Based_FAQ
Those are the grub's options menu.lst:

title           Knoppix
kernel          /boot/isolinux/linux ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 initrd=minirt.gz nomce quiet BOOT_IMAGE=knoppix
initrd          /boot/isolinux/minirt.gz
boot

Thank you!!!