bug#23072: GuixSD SSD install hangs at clocksource

[myglc2]

On 01/11/2017 at 23:31 Ludovic Courtès writes:

> myglc2 <address@hidden> skribis:
>
>> Florian Paul Schmidt <address@hidden> writes:
>>
>>> On 20.03.2016 20:56, myglc2 wrote:
>>>
>>>> - I did a near-identical install to a SSD (Kingston ssdnow300), see
>>>>   "c06system-ssd.scm.log". If installed on the 1st server this shows
>>>>   Guix welcome screen, loads the keyboard & mouse drivers, then hangs
>>>>   showing:
>>>> 
>>>>   "clocksource: Switched to clocksource tsc"
>>>
>>> This is just a shot in the dark, but I use SSD systems, too, and I
>>> noticed that the first boot of a guixsd installation hangs for a while
>>> collecting entropy before displaying a corresponding message IIRC and I
>>> faintly remember the "switching to clocksource" message. Did you try
>>> banging the keyboard? Maybe that's not possible on a headless server
>>> though. Did you let it sit for a while?
>>>
>>> Flo
>> Thanks Flo. Can't test that theory at the moment.  But I do have a
>> display attached (which is how I saw the "clocksource..." message).
>>
>> FWIW, in the HD install there is a prompt for keyboard input. It seems
>> like the SSD install hung before it reached that.  - George
>
> Any update on this bug?
>
>   http://bugs.gnu.org/23072
>
> Ludo’.

Hi Ludo,

I did experiments and I now see that this happens when the boot drive ID
has changed from what was specified as the grub-configuration device in
the most recent 'system init' or 'system reconfigure' operation.

This can happen, for example, when one moves drives around or when one
inserts a new drive in an empty lower SATA slot below drives holding
GuixSD.

This seemed like a bug to me because the doc says ...

   • Make sure the ‘grub-configuration’ form refers to the device you
     want to install GRUB on.

... but there is no mention that it affects boot operation.

Also I assumed, possibly wrongly, that GuixSD does not need the config
to tell it which device grub is on at boot because it is already running
on the boot device ;-)

So, I don't know ... Is this a bug or is this expected behavior.

If it is not a bug it seems like an opportunity to reduce the fragility
of GuixSD configurations.

HTH - George