Re: grubenv vs. diskfilter

[Andrey Borzenkov]

On Tue, Jun 18, 2013 at 10:57 PM, Phillip Susi <address@hidden> wrote:
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> On 6/3/2013 12:48 AM, Andrey Borzenkov wrote:
>> While grub itself can be installed on diskfilter devices (LVM,
>> Linux MD, ...), diskfilter devices are read-only. As grubenv is
>> automatically assumed to be in /boot/grub, this makes it impossible
>> to set variables from within grub. So grub cannot reset boot once
>> indicator, cannot save currently selected menu entry etc.
>
> I've been kicking around the thought that grub-pc should just put
> grubenv in the embed area attached to the core img, and grub-efi
> should put it in the ESP.

This still leaves the case when core.img cannot be embedded (and
adding extra space obviously increases chances of that) or delilberate
blocklist installs (openSUSE defaults to booting from partition). And
we still have PPC, SPARC and hopefully ARM to handle.

And we need some way for user space to auto-detect where environment
block is located ...

>                                         That would solve grubenv not working 
> on
> btrfs too.
>

Does btrfs guarantee that bootloader area is always located on a
single physical device?