Re: Installing the installer
Hi,
Richard Owlett wrote:
> > > xorriso -osirrox on ... -extract / /media/richard/netinst1
i wrote:
> > (This is just one way to copy the directory tree out of the ISO into
> > a disk tree. xorriso packs them up and packs them out.)
> I assumed that using xorriso on both ends would give me a "byte for byte"
> copy.
No, that's the job of "dd" or similar copy programs.
> > > 1. Grub2 will recognize it as a legit OS.
You will have to teach it by configuration file entries like described in
https://wiki.gentoo.org/wiki/GRUB2/Chainloading
https://superuser.com/questions/154133/grub-boot-from-iso
I wrote some remarks about that to Ethan Andrews in
"Re: How do I boot a Debian 9.1.0 amd64 iso from GRUB?"
https://lists.debian.org/debian-user/2017/09/msg00516.html
Your mileage may vary when the booted kernel expands its realm from
the initial RAM-disk to the ISO filesystem in the partition. It depends
much on the software in the initial RAM-disk and in the ISO whether
this will work.
Pascal Hambourg mentions problems with the initial RAM-disk content in
https://lists.debian.org/debian-user/2017/09/msg00566.html
Felix Miata pointed to the naked kernels and initial RAM-disk images
https://lists.debian.org/debian-user/2017/09/msg00568.html
I guess he means things like
http://ftp.nl.debian.org/debian/dists/testing/main/installer-amd64/current/images/hd-media/
sparsely described in
http://ftp.nl.debian.org/debian/dists/testing/main/installer-amd64/current/images/MANIFEST
> > > 2. if the partition is on a USB flash drive it will boot normally
> > > on suitable hardware.
If you do not want to modify the installed GRUB on the hard disk on that
system, then you will need a GRUB on that USB stick which gets preferred
by the firmware over the GRUB on hard disk, and then does the booting
of the operating system in the ISO.
> > > 3. all directories and files shall be modifiable.
> > But actually you want a runnable normal GNU/Linux.
> I want a "thingy/dodad/whatsit" that will install Debian to another
> location, be it device or partition.
If you do not want to unpack the ISO then you cannot directly modify files.
(I assume ISO 9660 multi-session is not what you intend, but rather
normal filesystem operations from the running operating system.)
So you would need a separate writable filesystem and overlay it over
the ISO when the operating system is running. But a Debian installation
ISO is not prepared for doing that out of the box, afaik.
So you would have to make your own ISO which has such capabilities.
The hard part is modifying an unpacked Debian installation ISO so that
it can do what you want when it gets started from an ISO in a partition.
Maybe the pieces mentioned by Felix Miata can help.
Packing up such ISO would not be difficult. One would not have to
make it bootable by firmware by MBR or EFI system partition, because your
USB stick's GRUB would be set up to be started by the firmwares.
Question at that point is of course why one would want to have a read-only
filesystem like ISO 9660 in the partition.
The only reason would be if one wants to easily reset the filesystem by
erasing the overlay filesystem, or if one could not get the Debian software
inside the ISO to work from some suitable read-write filesystem.
Have a nice day :)
Thomas
Reply to: