Re: Ubuntu mdadm Raid and EFI

[Jes Sorensen <Jes.Sorensen@redhat.com>]

On 11/24/11 17:11, Dominique wrote:
> Ok, nothing like writing a mail to get intuition for the next steps..
> 
> First I simplified the initial setup.
> RAID1 for everyone, and only two HDD to start. I'll convert and expand
> at a later stage.
> I also added an EFI partition ('bootgrup' if I remember well). I did
> that on both disk.
> Reboot and voila, it boots.
> 
> But this kind of negates the RAID1 /boot logic. If the first disk fail,
> then what ? No EFI, no boot ?
> How - if possible - do you configure EFI to boot from RAID1 across xHDD
> to allow boot in degraded mode ?

Depends on how you create your raid - if you use IMSM raid, you can put
the EFI partition on the raid1 device as well. Given you have a
motherboard with an i5 processor, I would expect it to have support for
IMSM raid.

Check the BIOS settings for the drives - if you flip them from AHCI to
raid mode you ought to be able to do it this way.

Cheers,
Jes