Bug#660776: Installation guide instructions for creating bootable USB stick don't work

[Samuel Thibault <sthibault@debian.org>]

tags 660776 + pending
thanks

Duncan Thomson, le Tue 21 Feb 2012 11:15:52 -0800, a écrit :
> The CD or DVD image you choose should be written directly to the USB stick,
> overwriting its current contents. For example, when using an existing GNU/Linux
> system, the CD or DVD image file can be written to a USB stick as follows:
> 
> # cat debian.iso > /dev/sdX
> # sync
> 
> This may work on debian, but I suspect most users are not going to have access
> to a debian system at this step.  On ubuntu the cat command above results in a
> "permission denied" error, even if done as root.

I guess by "done as root", you mean

$ sudo cat debian.iso > /dev/sdX

That's completely normal: with such syntax the '>' operation would
be done as the user, not as root.  There no other reason why *cat*
shouldn't work where dd would :) Actually, try

dd < debian.iso > /dev/sdX

You'll get the same behavior.

> # dd if=debian.iso  of=/dev/sdX
> # sync

That said, the advantage of that is that users who don't know the
subtelty of '>' with sudo will not hit it. I have comitted it.

> (Not sure if the "sync" is really required, is it?

Depends on a lot of things. It doesn't hurt in any case.

> Also, perhaps we should add a "umount" command in front of this,
> because if you insert a USB into most modern distros, it will
> automatically mount a file system on it,

Damn. Well, we can't really give a command, since it'll depend how the
key is formatted... But I have added a textual note.

> It might be nice to also give people instructions for how to do it on Windows,
> but unfortunately there's no simple way to provide that.

That's why we don't document it.

> Might be a good idea to include something like: "If you are using a
> different operating system, search the web for instructions on how to
> make a bootable USB stick from an iso image."

Which is actually not helpful at all :)

> p.s. Sorry, couldn't use "reportbug" to create this, since I don't yet have
> debian up and running.  Why isn't "reportbug" something that runs in a browser,
> so it can be invoked from anywhere?

Essentially because it would lower the barrier to filing bugs, and let
people who don't know how to report a bug report it anyway ("it doesn't
work" period).

Samuel