bug#29312: GRUB with multiple partitions with identical bzImage

[ludo@gnu.org (Ludovic Courtès)]

Vagrant Cascadian <vagrant@debian.org> skribis:

> On 2017-11-16, Ludovic Courtès wrote:
>> Vagrant Cascadian <vagrant@debian.org> skribis:
>> Indeed.  You can force GuixSD to use a file system label or a UUID by
>> declaring your file system with a label/UUID.  So you would write:
>>
>>   (file-system
>>     ;; …
>>     (mount-point "/")
>>     (title 'uuid)
>>     (device (uuid "f549617a-07b0-430a-9723-36c43b98c748")))
>
> Yes, this fixed it for me!

Awesome.

> For the record, spelling it out, apparently the issue wasn't searching
> in each menu entry, but:
>
>   # Set 'root' to the partition that contains /gnu/store.
>   search --file --set /gnu/store/0lwyzz8ayixwvdm1b3xhh26mlh0jz36b-grub-2.02/share/grub/unicode.pf2
>
> Where it set the initial root.
>
>
> After updating to mount by UUID, the corresponding search line became:
>
>   search --fs-uuid --set 1234ab-cdef-...1234ab
>
> So it then only loaded files from the appropriate filesystem.

I see.

> Since this is an issue caused by configuration, perhaps the
> documentation could clarify the importance of using UUID or filesystem
> labels rather than raw devices:
>
>   https://www.gnu.org/software/guix/manual/html_node/Proceeding-with-the-Installation.html#Proceeding-with-the-Installation

Currently it reads:

  Preferably, assign partitions a label so that you can easily and
  reliably refer to them in ‘file-system’ declarations

What would you suggest?

> I guess all of the install examples use labels:
>
>   http://git.savannah.gnu.org/cgit/guix.git/tree/gnu/system/examples/

Right.

> And I'm not sure how many people have multiple GuixSD installs on their
> systems, so perhaps it's just me putting myself into a corner case. :)

It’s arguably a corner case :-), but it’s better if it can be handled
correctly.

Thank you,
Ludo’.