From mboxrd@z Thu Jan 1 00:00:00 1970 From: Francis Moreau Subject: Re: Soft RAID and EFI systems Date: Tue, 04 Feb 2014 09:53:09 +0100 Message-ID: <52F0AA75.2030006@gmail.com> References: <70EFD3D5-F7AC-4359-8888-99EB6CCA9E4F@colorremedies.com> <52EEB9F2.2000607@gmail.com> <3D3B8F1A-F525-459D-95F2-9D7889C222CD@colorremedies.com> <52EECD53.30802@turmel.org> <52F0A79F.7090707@gmail.com> <52F0A976.9080306@hesbynett.no> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52F0A976.9080306@hesbynett.no> Sender: linux-raid-owner@vger.kernel.org To: David Brown , Phil Turmel , Chris Murphy Cc: linux-raid List-Id: linux-raid.ids On 02/04/2014 09:48 AM, David Brown wrote: > On 04/02/14 09:41, Francis Moreau wrote: >> On 02/02/2014 11:57 PM, Phil Turmel wrote: >>> On 02/02/2014 05:30 PM, Chris Murphy wrote: >>>> >>>> On Feb 2, 2014, at 2:34 PM, Francis Moreau >>>> wrote: >>>>> >>>>> That's funny because one of the reasons I want to use UEFI firmware >>>>> is to get rid of grub (I don't like it and the way it has become >>>>> such a bloated beast): since /boot is vfat and has its own >>>>> partition, I prefer use a much simpler bootloader such as >>>>> gummyboot. >>> >>> Ditching the bootloader is possible: >>> >>> http://kroah.com/log/blog/2013/09/02/booting-a-self-signed-linux-kernel/ >>> >> >> Well yeah it's possible but not currently usable IMHO. It means that you >> need to build your own kernel, include in this kernel the initramfs >> image and you need to redo the whole process if you want to change a >> single option in the kernel command line. >> >>> It seems to me that you should be able to create a raid1 v1.0 MD array >>> of your EFI support partitions, and put the combined and signed >>> kernel/initramfs onto it (mirrored to all member drives). >> >> Are both v0.9 and v1.0 MD put their metadata at the end of a partition >> ? I thought only v0.9 would do that. > > Yes, it is only 0.9 format that is at the end of the partition. This > means that a plain raid1 mirror (with as many disks as you like, as long > as they are simple mirrors and not raid10) looks just like a normal > partition for other tools. As long as it is read-only, tools that are > not raid-aware can use it. For example, grub and lilo can happily boot > from a 0.9 metadata raid1 array just like from a normal partition. > (Actually, modern grub understands a lot of md raid formats.) The same > thing should apply to EFI, as long as it does not attempt to write to > the partition. > hmm I need to check if EFI specifies that the ESP is never written by the firmware. If not it might be risky to rely on it.