Re: grub-install BIOS vs UEFI

[Chris Murphy]

On Dec 20, 2012, at 8:18 PM, Andrey Borzenkov <address@hidden> wrote:

> В Thu, 20 Dec 2012 11:16:29 -0700
> Chris Murphy <address@hidden> пишет:
> 
>> 
>> No what I'm asking for is for grub-install to automatically determine the 
>> member disks for an array and install multiple grub.efi's in each disk's 
>> ESP. It already does this for a single disk situation without having to 
>> specify a device, I don't want to have to specify multiple locations 
>> manually. It should be automatic.
>> 
> 
> grub-install simply looks for /boot/efi, /boot/EFI and is using root
> directory as last resort if it is FAT. That's all. I would not call
> this "automatic" - someone has to mount /boot/efi first and this is
> manual step.

I understand, that makes sense. I was thinking maybe it could identify 
constituent members of the RAID via /proc/mdstat or whatever, and then locate 
the ESP on those physical devices using the partition type GUID for ESP, and 
then drop grub.efi into the proper place on each one.

But this is not just about grub.efi, there are other components on the ESP, 
like EFI SB shims and such.

> I think this is task for higher level system configuration tools - to
> decide or ask user which partitions are boot partitions and where
> bootloader has to be installed. Right now you designate filesystem to
> be mounted as /boot/efi during installation. Manually. In future you
> may allocate multiple partitions. One just need to come up with sane
> scheme to name them :)

like lsyncd or something - lazy sync is fine. A self-replicating boot loader 
mechanism that makes it difficult to arrive at a non-bootable system even if a 
drive fails sounds good.

I suppose for security reasons this isn't the realm of an EFI boot manager to 
have write capability to the ESP? If that's not a hideously bad idea, a 
non-default user option to sync ESPs on reboots could be employed there, and 
the boot manager would do it on each boot.


> And this is not really GRUB2 specific. I had the same question recently
> about RHEL6 on UEFI system and you can do it with elilo as well. You
> need some higher-level framework to keep content of multiple ESPs in
> sync.


I've only recently discovered that GRUB will find its mod files in /boot/grub 
on RAID 0, 1, 4, 5, and 6. That's probably old news. But with that many levels 
supported, all the more reason /boot can be on RAID.



Chris Murphy