howto create a bootable livesystem usb stick, which boots iso images with grub2

• boot linux (debian/ubuntu/.. running grub2)
• become root (su / sudo -i)
• attach usb stick
• find device of the stick

fdisk -l

• replace sdX by the usbstick device you found in the next steps!

• mount stick

mkdir /mnt/usb
mount /dev/sdX1 /mnt/usb

• install grub to stick:

grub-install --force --no-floppy --root-directory=/mnt/usb /dev/sdX

• edit grub.cfg config to match your iso files -

edit /mnt/usb/boot/grub/grub.cfg

• example grub.cgf:

###   MultiBootStick
#     grub2 direct ISO boot config

menuentry "ubuntustudio-12.04-dvd-amd64" { 
    set isofile="/iso/ubuntustudio-12.04-dvd-amd64.iso"
    loopback loop $isofile 
    linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile noeject noprompt -- 
    initrd (loop)/casper/initrd.lz
}

reboot from stick - have fun :)