Why not hybrid iso/flash image?

[Michał Karaś]

Hi.
Did you heard about hybrid iso/flash images? If no please read here:
http://wiki.geteasypeasy.com/Hybrid_ISO/IMG_format#How_the_Hybrid_ISO.2FIMG_works
http://www.syslinux.org/wiki/index.php/Doc/isolinux#HYBRID_CD-ROM.2FHARD_DISK_MODE

Why bother with extracting files and running some scripts, when you
can just "cat" or "dd" the image on to the usb stick or even hard
disk?
This is not something important, but I think it is worth consideration.

[Joanna Rutkowska]

Sure, would be nice to have it -- have you considered to submit a patch?

joanna.

[Michał Karaś]

It is enough to just run isohybrid command over
the iso:
http://www.syslinux.org/wiki/index.php/Doc/isolinux#HYBRID_CD-ROM.2FHARD_DISK_MODE

I tried it with Qubes iso and it works!
I did not test whole installation process, just booted the installer
and it seems to be OK.

I browsed trough the code repository and found this file:
http://git.qubes-os.org/gitweb/?p=mainstream/installer.git;a=blob;f=anaconda/scripts/mk-images.x86

look at lines 133-135 - I thought it may be funny if the build process
already generates hybrid image - so i tested raw unchanged Qubes Iso
beta 3 - however this time it did not work.

So it seems to me that there are two possibilites - either for some
reason there is no isohybrid in /usr/bin on your build system, or
there is some bug in isohybrid that is fixed in never version. I used
version 4.04 of syslinux, and it seems that your build system requires
syslinux 3.73 according to this file:
http://git.qubes-os.org/gitweb/?p=mainstream/installer.git;a=blob;f=anaconda/anaconda.spec

syslinux changelog lists many bugs fixed in isohybrid since version 3.73

[Joanna Rutkowska]

On 04/06/12 16:59, Michał Karaś wrote:
> It is enough to just run isohybrid command over
> the iso:
> http://www.syslinux.org/wiki/index.php/Doc/isolinux#HYBRID_CD-ROM.2FHARD_DISK_MODE
>
>
> I tried it with Qubes iso and it works!
> I did not test whole installation process, just booted the installer
> and it seems to be OK.
>
> I browsed trough the code repository and found this file:
> http://git.qubes-os.org/gitweb/?p=mainstream/installer.git;a=blob;f=anaconda/scripts/mk-images.x86
>
> look at lines 133-135 - I thought it may be funny if the build process
> already generates hybrid image - so i tested raw unchanged Qubes Iso
> beta 3 - however this time it did not work.
>
>
> So it seems to me that there are two possibilites - either for some
> reason there is no isohybrid in /usr/bin on your build system, or
> there is some bug in isohybrid that is fixed in never version. I used
> version 4.04 of syslinux, and it seems that your build system requires
> syslinux 3.73 according to this file:
> http://git.qubes-os.org/gitweb/?p=mainstream/installer.git;a=blob;f=anaconda/anaconda.spec
>
> syslinux changelog lists many bugs fixed in isohybrid since version 3.73

Thanks! We will test this the next time we will be building a new ISO
(in the coming weeks I think). For now I updated the ticket #440 to
contain a reference to your message.

joanna.