Re: Raid5 boot failure after grow

[Phil Turmel <philip@turmel.org>]

On 07/19/2011 06:43 PM, Shaun Reich wrote:
> Hello,
> 
> I'm using Fedora 15 and I added an additional disk to my raid5 setup
> and grew the array to encompass it. It all worked fine and rebuilt and
> everything. However, now when I boot my computer I am dropped to a
> shell, stating "dracut" (I wonder what that means). Anyways, when in
> here I can cat /etc/mdadm.conf and it appears to be an old
> configuration file. It lists only 3 raid devices in that
> configuration. I now have 4.

dracut is the "new" cross-distribution initramfs environment.  I'm using it in my gentoo boxes.

> If I run mdadm --assemble --scan after removing the config file, it
> will automatically find my array and all is well. But this doesn't
> solve the fact that it doesn't boot to it.
> 
> dmesg reports "no root device
> 'block:/dev/disk/by-uuid/933ac67-98f1-481f-934e-c9af492ba28c' found"
> 
> This is particularly interesting, because blkid lists /dev/md127
> (after I've managed to mount it), as that same UUID.
> 
> fyi, I use GRUB to boot to a /boot partition, which is then supposed
> to mount the array. Is there anything obvious that I have missed? Do I
> have to rebuild the initrd, or something like that? (since it seems
> the fallback shell doesn't preserve any changes to /etc/mdadm.conf).

Yes, your initramfs needs a current copy of your mdadm.conf file, if it has any at all.

HTH,

Phil