Re: [PATCH] Add GRUB_DISABLE_UUID.

[Daniel Kiper]

On Thu, Sep 19, 2019 at 02:20:06PM +0200, Javier Martinez Canillas wrote:
> Hello Daniel,
>
> On 9/18/19 2:39 PM, Daniel Kiper wrote:
> > Adding Nicholas...
> >
> > On Tue, Sep 17, 2019 at 05:48:45PM +0200, Javier Martinez Canillas wrote:
> >> From: Peter Jones <address@hidden>
> >>
> >> This will cause "search --fs-uuid --set=root ..." not to be generated by
> >> grub2-mkconfig, and instead simply attempt to use the grub device name
> >> as it understands it.
> >>
> >> Signed-off-by: Peter Jones <address@hidden>
> >> Signed-off-by: Javier Martinez Canillas <address@hidden>
> >
> > We have this functionality in GRUB upstream. Please take a look at
> > commit 51be3372e (templates: Update grub script template files).
> > Could you pick it up in RH/Fedora?
> >
>
> That commit does something different if I'm reading it correctly. It's about
> allowing to set the root kernel command line parameter to a PARTUUID instead
> of a UUID or a device name, by using the grub-probe --target=partuuid option.
>
> But Peter's patch is about setting the root param to a device name instead
> of a UUID.
>
> And also about not adding search commands in the grub.cfg to set the $root
> and $boot grub environment variables by searching using a UUID.
>
> Now digging more I found that there's already a GRUB_DISABLE_LINUX_UUID option

There are two variables: GRUB_DISABLE_LINUX_UUID and 
GRUB_DISABLE_LINUX_PARTUUID.

> for the first part, so we only need to add an option for the second part.

OK.

> Since this is not about Linux not using a UUID but grub not using it, I think
> that we should add another option as this patch does. So 
> GRUB_DISABLE_LINUX_UUID
> would disable using a UUID for the root param and GRUB_DISABLE_UUID would be
> about disabling using a UUID to set the $root (and $boot) variables in grub.
>
> GRUB_DISABLE_UUID=true probably should imply GRUB_DISABLE_LINUX_UUID=true also

OK but only if GRUB_DISABLE_LINUX_UUID is not set explicitly. And what
about GRUB_DISABLE_LINUX_PARTUUID?

> I think. But I guess is OK to have separate options and the user could set 
> both
> if want to disable using the UUID for Linux and grub.
>
> Another option is to extend GRUB_DISABLE_LINUX_UUID semantics and don't add
> search commands if this is set to true, but I'm not sure if that's correct.

Hmmm... Probably I prefer former approach...

Daniel