[ale] SW RAID install problem - can't find root on raid at boot time

[Jeff Hubbs]

Having all manner of trouble with this.

Two SATA drives; onboard RAID disabled in favor of SW RAID:

  ptn |   1   |   2   |   3   |
 disk ------------------------
  sda | /boot |  md1  |  md2  |
  sdb | spare |  md1  |  md2  |

The goal here is to mount /dev/md1 at boot.

At boot, I get:

  md: autodetecting raid arrays
  md: autorun...
  md: ...autorun done
  VFS: cannot open root device "md1" or unknown-device(0,0)
  please append a correct "root=" boot option
  Kernel panic - not syncing: vfs : unable to mount root fs on
unknown-block(0,0)

I have been using http://tinyurl.com/mauwd for guidance.  I am not now
dealing with LVM (that will involve /dev/md2, after I get this machine
booting on its own.

Let me try to cover the more obvious things:
  * SATA, the SATA chipset in question, device mapper support, and RAID
1 are all compiled into the kernel.
  * /etc/mdadm.conf looks like

        DEVICE /dev/sd[ab][23]
        ARRAY /dev/md2 level=raid1 num-devices=2
UUID=833313e0:55a9f505:b67e7c38:af37019a
        ARRAY /dev/md1 level=raid1 num-devices=2
UUID=b67bd189:933757ef:ef6dff61:50ad811a

    (Note: the two ARRAY lines were generated with mdadm --detail --scan
when booted to a livecd with
     the RAID volumes up and running)
  * /dev/sd[ab][23] are all of partition type fd.
  * /dev/md1 and /dev/md2 are fundamentally sound; I can boot to a
LiveCD, modprobe raid1,
    mdadm --assemble, and mount them right up with no problem.

I made a point of not being module-dependent at boot.  I have no initrd,
and the doc I linked to above likewise has no initrd. 

Anything here I've missed?

- Jeff