From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Subject: Re: Ubuntu mdadm Raid and EFI Date: Mon, 28 Nov 2011 10:44:20 +0100 Message-ID: <4ED357F4.3050605@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Dominique Cc: linux-raid mailing list List-Id: linux-raid.ids 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