Hi Thomas, Thank you for the clearly defined steps on reducing the size of the ISO. However I didn't have a working Linux system to perform those steps with. I ended up just putting the iso I had onto a 16GB USB stick to get my computer working again. I just thought I'd let you know I appreciated the effort in guiding me through shrinking the image myself, it was very well written and clear.
Tim McConnell On Mon, Sep 22, 2025 at 2:15 AM Thomas Schmitt <[email protected]> wrote: > > Hi, > > Tim MCCONNEL wrote: > > I got the image from: cdimage.debian.org/Debian-cd/current/amd64/iso-cd > > Downloading > > http://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-13.1.0-amd64-netinst.iso > yields a downloaded file with 821,035,008 bytes = ~0.8 GB. > > Thus my first proposal is to just try putting it on your 8 GB stick > and to see what happens. > > > But for the sake of science let's assume that you really have problems > with an oversized Debian ISO. > > In this case i would try to repack it while removing a few files, of > which i believe that i won't need them. The obvious candidates in the > netinst ISO are the firmware files. In larger Debian ISOs there may be > some other big .deb files which you may decide not to need. > > Mount the ISO > > mkdir /mnt/iso > > mount debian-13.1.0-amd64-netinst.iso /mnt/iso > > Look for big firmwware files which your hardware will not need. > > find /mnt/iso -exec ls -ld '{}' ';' 2>&1 | less > > yields lines like > > -r--r--r-- 2 root root 29474828 Apr 24 22:47 > /mnt/iso/firmware/firmware-atheros_20250410-2_all.deb > ... > -r--r--r-- 2 root root 39481748 Apr 24 22:47 > /mnt/iso/firmware/firmware-nvidia-graphics_20250410-2_all.deb > > That's 70 MB. It might be difficult to find another 130 MB of unneeded > stuff in the 800 MB of netinst. > > The firmware files in ISO directory > /firmware/ > are hardlinked with files in the > /pool/non-free-firmware/*/firmware-nonfree/ > directories. In case of the above two: > > -r--r--r-- 2 root root 29474828 Apr 24 22:47 > /mnt/iso/pool/non-free-firmware/f/firmware-nonfree/firmware-atheros_20250410-2_all.deb > -r--r--r-- 2 root root 39481748 Apr 24 22:47 > /mnt/iso/pool/non-free-firmware/f/firmware-nonfree/firmware-nvidia-graphics_20250410-2_all.deb > > You'd need to remove both file paths of each file in order to get rid > of their content in the ISO. > > After having made the decision which files to remove, you may create > the new ISO filsystem according to > > https://wiki.debian.org/RepackBootableISO#In_xorriso_load_ISO_tree_and_write_modified_new_ISO > > That would be: > > umount /mnt/iso > > xorriso \ > -indev debian-13.1.0-amd64-netinst.iso \ > -outdev debian-13.1.0-amd64-custom.iso \ > -rm /firmware/firmware-atheros_20250410-2_all.deb \ > /firmware/firmware-nvidia-graphics_20250410-2_all.deb \ > > /pool/non-free-firmware/f/firmware-nonfree/firmware-atheros_20250410-2_all.deb > \ > > /pool/non-free-firmware/f/firmware-nonfree/firmware-nvidia-graphics_20250410-2_all.deb > \ > -- \ > -boot_image any replay \ > -compliance no_emul_toc \ > -padding included > > This xorriso run is supposed to report > ----------------------------------------------------------------------- > ... > Drive current: -indev 'debian-13.1.0-amd64-netinst.iso' > Media current: stdio file, overwriteable > Media status : is written , is appendable > Boot record : El Torito , MBR isohybrid cyl-align-on GPT APM > Media summary: 1 session, 400896 data blocks, 783m data, 340g free > Volume id : 'Debian 13.1.0 amd64 n' > ... > Drive current: -outdev 'debian-13.1.0-amd64-custom.iso' > ... > Removed from ISO image: file '/firmware/firmware-atheros_20250410-2_all.deb' > Removed from ISO image: file > '/firmware/firmware-nvidia-graphics_20250410-2_all.deb' > Removed from ISO image: file > '/pool/non-free-firmware/f/firmware-nonfree/firmware-atheros_20250410-2_all.deb' > Removed from ISO image: file > '/pool/non-free-firmware/f/firmware-nonfree/firmware-nvidia-graphics_20250410-2_all.deb' > xorriso : WARNING : -volid text problematic as automatic mount point name > xorriso : WARNING : -volid text does not comply to ISO 9660 / ECMA 119 rules > xorriso : NOTE : Replayed 22 boot related commands > ... > Written to medium : 367104 sectors at LBA 0 > Writing to 'debian-13.1.0-amd64-custom.iso' completed successfully. > ----------------------------------------------------------------------- > So the file debian-13.1.0-amd64-custom.iso is about 33000 sectors of > 2048 bytes smaller than the original ISO. > > (The warning about the -volid text is due to blanks, dot, and lower > case letters in the Volume Id text "Debian 13.1.0 amd64 n".) > > Inspection by > x=debian-13.1.0-amd64-netinst.iso > xorriso -indev $x -report_el_torito plain -report_system_area plain > and > x=debian-13.1.0-amd64-custom.iso > xorriso -indev $x -report_el_torito plain -report_system_area plain > shows the same (quite entangled) boot equipment in both ISOs. > > The remaining question is, whether the debian-installer tolerates the > missing of the two firmware files. One will have to try. > > > I wrote: > > > i'm chiming in because your mail address is not subscribed to this > > > list (you could do at https://lists.debian.org/debian-cd ) and because > > > the two answers so far did not Cc your mail address. > > Tim MCCONNEL wrote: > > Sorry if I broke the rules. > > No rules were broken. It's just unusual on the Debian lists to Cc > the original poster of a mail thread. So i felt the need to justify my > Cc to you. > Debian mailing lists add a header X-Spam-Status where the word > LDOSUBSCRIBER indicates that the sender is subscribed to the list. > When i don't see it, i assume that the sender will not receive messages > which are sent only to the list. > > > Have a nice day :) > > Thomas >
