The Startup Disk Creator is glitchy when I try to use non-Ubuntu iso files

[sudodus]

The current version of the Ubuntu Startup Disk Creator (in Ubuntu 16.04 LTS and newer versions of Ubuntu) is easy to use. And it is a cloning tool, which makes it reliable.

It seems dedicated to creating USB boot drives for Ubuntu and Ubuntu family flavours (Kubuntu, Lubuntu ... Xubuntu).

I have tested with various iso files outside the Ubuntu family:

- Respins based on Ubuntu are usually accepted as input

- A few respins based on Debian are also accepted as input

- Debian 10 live iso files are not accepted (they do not appear in the box for input files after selecting them).

- Other main linux distros for example Fedora and OpenSUSE are not accepted.

This is rather confusing and I concluded, that there is some filter, that decides which iso files to accept. So I checked in the Python code.

In the file /usr/lib/python3/dist-packages/usbcreator/backends/udisks/backend.py there is

def _is_casper_cd(self, filename):
    for search in ['/.disk/info', '/.disk/mini-info']:
        cmd = ['isoinfo', '-J', '-i', filename, '-x', search]
        try:
            output = misc.popen(cmd, stderr=None)
            if output:
                return output
        except misc.USBCreatorProcessException:
            # TODO evand 2009-07-26: Error dialog.
            logging.error('Could not extract .disk/info.')
    return None

which indicates that the Startup Disk Creator is checking for the content of the files /.disk/info and /.disk/mini-info.

These are present in Ubuntu, Debian and many but not all respins. The funny thing is that the difference between Debian 10.2 and Kali is a trailing line feed. I checked with Debian 8.8. It contains a newline and is accepted by the Startup Disk Creator.

sudodus@bionic64 /media/multimed-2/CD/debian $ sudo mount -o loop debian-live-8.8.0-amd64-standard.iso /mnt/lp1
mount: /mnt/lp1: VARNING: enhet skrivskyddad, monterad som endast läsbar.
sudodus@bionic64 /media/multimed-2/CD/debian $ cat /mnt/lp1/.disk/info
Debian GNU/Linux 8 "Jessie" - Official Snapshot amd64 LIVE/INSTALL Binary 20170506-14:26
sudodus@bionic64 /media/multimed-2/CD/debian $ sudo mount -o loop debian-live-10.2.0-amd64-standard.iso /mnt/lp2
mount: /mnt/lp2: VARNING: enhet skrivskyddad, monterad som endast läsbar.
sudodus@bionic64 /media/multimed-2/CD/debian $ cat /mnt/lp2/.disk/info
Official Debian GNU/Linux Live 10.2.0 standard 2019-11-16T10:15sudodus@bionic64 /media/multimed-2/CD/debian $

So it seems that I have found a bug. The Startup Disk Creator does not accept an iso file unless there is a trailing newline character in the file /.disk/info or /.disk/mini-info.

-o-

I suggest

1. Bug-fix

Modify the code so that it will also accept an iso file with a file '/.disk/info' or '/.disk/mini-info' even if there is no newline character.

This would make the Startup Disk Creator more useful for all the people who use Ubuntu or an Ubuntu community flavour as their main operationg system, but want to try Debian 10 live (and maybe also future Debian versions).

2. Improvement

Make the Startup Disk Creator accept all iso files as input, but pup up a message with a disclaimer when the iso file is not identified as an Ubuntu family iso file (the string 'buntu' is not found in one of '/.disk/info' or '/.disk/mini-info', or none of the files is found at all). The file name should be enough to identify the input file.

This would make the Startup Disk Creator useful also for people who want to try other (non-Ubuntu and non-Debian) Linux operating systems that provide hybrid iso files.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: usb-creator-gtk 0.3.5ubuntu18.04.2
ProcVersionSignature: Ubuntu 4.15.0-74.84-generic 4.15.18
Uname: Linux 4.15.0-74-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.9
Architecture: amd64
CurrentDesktop: LXDE
Date: Tue Jan 21 08:40:28 2020
InstallationDate: Installed on 2018-05-15 (615 days ago)
InstallationMedia:

SourcePackage: usb-creator
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Wolf Pichler (w-pichler)]

While it is possible to create a bootable Stick from an original Ubuntu 20.04 iso it does not work for a modified one - even though the /.disk/info files are identical.

It even depends on the name of the source iso how Startup Disk Creator behaves.
If it does not contain "Ubuntu", the window in the end just contains one "Quit" button.
If it does, the window has two buttons - "Test Disk" and "Quit".

Both sticks are unusable though.

The last time I know Startup Disk Creator worked for my modified iso files was in Ubuntu Trusty.

[sudodus (nio-wiklund)]

@Wolf Pichler,

I understand that you write this comment because you want the Ubuntu Startup Disk Creator to be improved.

But that you do not use it since the days of Trusty. At that time it was an extracting tool with ability to create persistent live drives, and I think it was buggy. In Ubuntu Xenial (16.04 LTS) it was converted to a cloning tool and less buggy (creating only live-only drives), but not willing to copy non-Ubuntu iso files.

It would be interesting to know what kind of tool you want it to be.

By the way, many modern linux distros provide iso files, that when cloned create persistent live drives, and with an additional menu entry (built into the iso file) Ubuntu would be able to do that too.

[Wolf Pichler (w-pichler)]

Correction:

On Bionic:
If it does contain "Ubuntu", the window in the end just contains one "Quit" button.
This is also the case after creating a bootable Stick from an original Ubuntu 20.04 iso.

If it does not contain "Ubuntu", the window has two buttons - "Test Disk" and "Quit".

On Focal:
In both cases the window in the end just contains one "Quit" button.

[sudodus (nio-wiklund)]

You can trick the Startup Disk Creator to clone non-Ubuntu iso files, because it is willing to clone 'any' image file with the extension img. So make a symbolic link, for example

$ ln -s debian-live-11.0.0-amd64-standard.iso debian-live-11.0.0-amd64-standard.img
$ ls -ltr
total 924676
-rw-r--r-- 1 lubuntu lubuntu 946864128 Aug 18 13:02 debian-live-11.0.0-amd64-standard.iso
lrwxrwxrwx 1 lubuntu lubuntu 37 Oct 11 11:18 debian-live-11.0.0-amd64-standard.img -> debian-live-11.0.0-amd64-standard.iso

I tested this in 18.04.x LTS with usb-creator-gtk and in persistent live Lubuntu Impish Indri with usb-creator-kde, and it worked for me.