FC14 problem "no root device found"

[Bruno Wolff III]

On Fri, Oct 07, 2011 at 20:25:50 +0200,
  Gijs <info at bsnw.nl> wrote:
> 
> I created a raid-1 device for the /boot partition. I copied my existing 
> boot to /boot and my existing root to the LVM-volume that is ontop of a 
> raid-5 device. I tried booting from it, but I just can't get it to mount 
> the root right after it boots the kernel. I get the message "no root 
> device found".
> 
> I pretty much tried everything. I recreated the initrd because I thought 
> it might have something to do with the raid device (which I didn't have 
> before). But after inspecting the initrd contents of my original stock 
> kernel, I found mdadm and other raid-related files. So I figured that 
> shouldn't be the problem.
> 
> I tried specifying the root partition in a number of ways. By UUID, by 
> "/dev/mapper/raid--5--lvm-root", by "/dev/md-0", by "/dev/raid-5/root", 
> by label "root". Nothing worked.
> 
> Does anyone have any idea how to solve this?

Did you update fstab and mdadm.conf on the new system and rerun dracut?
(I usually use the kernel update script to rerun dracut so I don't
need to remember the options.)

The initramfs includes information about which devices to activate before
doing the root pivot. If you don't have the raid array for root in mdadm.conf
the array won't be started and hence won't be available to change to.

You might need to do something similar for lvm. I don't use it, so I don't
need to worry about it.