Bug#534887: live-initramfs: Loop mounting .iso for booting from multi-purpose USB stick?

[Philip Hands <phil@hands.com>]

Package: live-initramfs
Severity: wishlist


Hi,

I've been trying to build a versatile USB stick, with the imntent that
it be able to choose between various images at a grub prompt.  Some
.iso images (i.e. http://partedmagic.com/) are happy with this setup,
becasue once booted (via grub4dos's ability to map a .iso and boot it)
they look around for the image they came from and loop mount it, in much
the same way as debian-live looks for its .squashfs

debian-live does not appear to have this ability at present, although
given that it can find the .squashfs I'd guess it's not going to be
too hard to add, but I'm afraid my cursory glance over the code did not
reveal the place where it should be added.

Of course, it's possible to extract the .squashfs and put that on the stick:

  http://wiki.hands.com//howto/ultimate-usb-stick/#gettingdebian-livetorun

but that seems like a bit of a kludge.

I realise that there's already a usb-hdd target, but that involves wiping
out the USB stick, which is tiresome, especially in these days of ever
growing capacity.

It seems to me that the ability to have a selection of .ISO's on a stick,
and upgrade them as you see fit adds another dimension of conveinience.

There is at least one gotcha though -- grub will often fail to map an
image if it's fragmented, so you're liable to have to copy all the images
off the stick, delete them and then write them back to make it happy.
The --mem option to grub's map command is supposed to handle that case,
by copying the image to ram, but I've not had a lot of luck with that.
Note that when I say grub here I'm talking about grub4dos which is pretty
much the same as grub2, but seems to deal with the vagaries of USB-ZIP
rather better than grub2 at the moment.

Cheers, Phil.

-- System Information:
Debian Release: 5.0
  APT prefers unstable
  APT policy: (50, 'unstable')
Architecture: i386 (i686)

Kernel: Linux 2.6.26-1-686 (SMP w/1 CPU core)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash