Start the chroot, and then, from a non-root, non Debian prompt, type the following: Code: mkdir -p /media/mmc1/apt-archives/partial sudo mount -o bind /media/mmc1/apt-archives /debian/var/cache/apt/archives This will make a cache directory on your MMC card (you can change mmc1 to mmc2 if you want) and then tells Debian to use that to store all of the downloaded packages.
mkdir -p /media/mmc1/apt-archives/partial sudo mount -o bind /media/mmc1/apt-archives /debian/var/cache/apt/archives