Re: How can I diagnose a startup failure on a live USB?

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Miles Fidelman <mfidelman@meetinghouse.net> writes:

> On 9/9/17 12:50 PM, Efraim Flashner wrote:
>
>> On Fri, Sep 08, 2017 at 03:03:24PM +0200, David Seaward wrote:
>>> Hi all,
>>>
>>> I am trying to run Guix SD from a live USB on two machines. On machine
>>> A this works: I can select "linux-libre" from GRUB and the startup
>>> process runs, ending with a prompt on TTY 1 and documentation on TTY 2.
>>>
>>> On machine B, the startup process runs but towards the end (ssh-
>>> keygen... ncsd...) the screen goes black and I can't switch between
>>> TTYs.
>>>
>>> How can I diagnose the cause of this problem? Even enough to report an
>>> error message.
>>>
>>>
> Perhaps see if there's a way to set more verbose logging with a boot
> parameter, and find a way to capture the console messages (e.g., use a
> serial console, and a software TTY emulator).  That will at least tell
> you where things stop working.  You can start debugging from there.

+1. You could also probably get by via SSH. Check the output of `dmesg'
from there. I had a system recently which would blackscreen on me at the
login screen. The issue was related to the amdgpu driver (nothing to do
with GuixSD though, that was on Debian).

Good luck!

Maxim