Re: Installation media couldn't be mounted

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

John Paul Adrian Glaubitz wrote:
> Tools like Rufus make weird assumptions and it has happened more
> than once that one of these imaging tools create unusuable installation
> media [1].

That's the other mode of Rufus, which unpacks the ISO onto the USB stick,
interprets its bootloader menu, and adds entries to the menu of the
bootloader which it installed on the stick. (Caution: hearsay.)

It might be that Rufus' automatic switch to "dd" does not recognize
a Debian powerpc ISO as suitable. But afaik this depends on the presence
of a MBR partition table, which the powerpc ISOs have.
There should also be a button for manual switch to "dd" mode.


> If someone wants to deviate from the tested standard way, they're on their
> own.

Well, the litmus test would be whether xorriso reports the same about
image and USB stick:

  iso=...path.to.iso.image.file...
  stick=stdio:/dev/sdb

  xorriso -indev "$iso" -report_system_area plain >/tmp/xorriso_report_iso

  xorriso -indev "$stick" -report_system_area plain >/tmp/xorriso_report_stick

Then

  diff /tmp/xorriso_report_iso /tmp/xorriso_report_stick

should show no differences.


But already if

  xorriso -indev "$stick"

reports about the 2019-07-03 ISO on stderr:

  xorriso : NOTE : Loading ISO image tree from LBA 0
  ...
  Boot record  : (system area only) , MBR CHRP cyl-align-off APM
  Media summary: 1 session, 152404 data blocks,  298m data, 1614m free
  Volume id    : 'Debian 10.0 ppc n'

or about the 10.0.0 ISO:

  xorriso : NOTE : Loading ISO image tree from LBA 0
  ...
  Boot record  : (system area only) , MBR CHRP cyl-align-off APM
  Media summary: 1 session, 159262 data blocks,  311m data,  310g free
  Volume id    : 'Debian 10.0.0 ppc n'

it is quite clear that the copy mode was plain "dd" and not unpacking.

(xorriso will by default not touch /dev/ files which are not optical drives.
The prefix "stdio:" tells it that the user is aware of the non-CD nature
of the device.)


Have a nice day :)

Thomas