[arch-dev-public] LVM/MDADM and GRUB2

[Pierre Schmitz]

Am Mittwoch, 10. März 2010 07:47:23 schrieb Tobias Powalowski:
> has anyone succeeded in having /boot on a lvm volume, or a mdadm raid
> device,  which grub2 can directly boot from it?
> 
> If yes please give me some advice how to do it, i want to add full grub2 
> support to archboot setup and the docs are quite messy. I haven't found a
> way  to do such a setup.

I am using raid5 with grub2. And yes, documentation is rareso I probably 
solved it the stupid way. I couldn't create my raid on the bare drives like 
sda, sdb, sdc etc. as there wont be enough space for the grub2 boot loader.

So I create one big partition on each drive and created a raid with sda1,sdb1 
etc.. Then I was able to install the bootloader to each of those drives (sda, 
sdb etc.) Within the raid I have created the actual partitions; so this setup 
looks a little weird but totally works.

My grub.cfg looks like this:

set timeout=1
set default=0

insmod raid
insmod raid5rec
insmod mdraid
insmod ext2

set root=(md0,1)

menuentry "Arch Linux" {
        linux /boot/vmlinuz26 root=/dev/md0p1 ro
        initrd /boot/kernel26.img
}

Interesting is that I couldn't use labels here for the kernel root partition. 
(maybe its initcpio related and already fixed)

And you might need to load those raid and mdraid modules and set the root to 
md0 instead of hd0 etc..


-- 

Pierre Schmitz, https://users.archlinux.de/~pierre