Re: repair broken boot record

[Thomas Danckaert <post@thomasdanckaert.be>]

Hello Florian,

thank you for your help.  I managed to chroot into my system, and re-run 
'guix system reconfigure' (very useful mailing list discussion on 
chrooting, I also vote for including it in documentation :) ).  In one 
of the final steps, where guix tries to install the bootloader, I get 
the error:

/gnu/store/.../grub/i386-pc/modinfo.sh doesn't exist. Please specify 
--target or --directory.

Indeed my system uses grub-efi.  Could that be related?  Can you point 
me to some specific instructions on how to check/solve efivar issues?

Not sure if I need grub-efi, or if it might also work using grub-pc.  
Until now I've always used grub-efi.

(Another thing I noticed (maybe a side effect of chroot?): when I re-run 
'guix system reconfigure' it tries to rebuild derivations that are 
already there in the store from last time, I think.)

thank you!

Thomas

On 2021-10-01 08:53, pelzflorian (Florian Pelz) wrote:
> On Thu, Sep 30, 2021 at 09:43:18AM +0200, Thomas Danckaert wrote:
>> Hello guix-help,
>> 
>> my system does not boot anymore after a guix pull and system 
>> reconfigure
>> (which did show a warning, see below).  It does not even enter the 
>> GRUB
>> stage, I get a "Reboot and Select proper Boot device" instead.  I 
>> think the
>> MBR might not have been written correctly (just a hunch, I'm no 
>> expert...).
> 
> If this system uses no old grub-bootloader but instead EFI
> (grub-efi-bootloader), maybe writing the bootloader to the mainboard
> failed (it is not only written to disk), perhaps because the mainboard
> NVRAM is full and needs to be cleaned with efibootmgr/efivar/such
> utilities.
> 
> 
>> During reconfigure, I did get a warning that my bootloader 
>> configuration
>> used 'target', which is apparently deprecated in favor of 'targets'.  
>> I
>> wasn't paying too much attention, and ignored the warning.... I don't 
>> know
>> if that could be the cause of a missing or incorrect boot record?  (In 
>> that
>> case, I suggest this warning should be an ERROR ;-) )
> 
> No, the old target would fall back to targets.  The warning is only a
> warning that you should switch to (targets (list "…")).
> 
> 
> 
>> I checked using a live USB, and it seems the whole system is still 
>> there on
>> the hard drive.  Is there a way to restore my system, keeping the 
>> existing
>> /gnu/store?  Or do I have to reinstall from scratch, remove the 
>> existing
>> /gnu/store and rebuild everything (shouldn't be too much work using 
>> Guix,
>> but way less elegant :) )
>> 
>> Thank you!
>> 
>> Thomas
> 
> I search on Duckduckgo for “site:lists.gnu.org guix chroot”, you
> should read there how to chroot into your system so you can
> reconfigure.
> 
> Regards,
> Florian