Trouble booting off an md device with grub 1.99

[Bernie Innocenti]

(adding bug-grub@)

Hello,

I've created an md root partition on a couple of drives and installed
grub in the master boot record the usual way:

 mount --bind /dev  /newroot/dev
 mount --bind /sys  /newroot/sys
 mount --bind /proc /newroot/proc
 chroot /newroot
 grub-install /dev/sda
 grub-install /dev/sdb
 exit
 # umount everything and reboot

After this, the machine won't boot off the new drives. It will simply
hang with a black screen after the POST, when the grub menu would
normally come up. It looks almost like the mbr can't locate the blocks
to load next.

I also tried booting off a USB stick and using --boot-directory from the
live distro rather than chrooting. I also tried specifying '(hd0)' and
'(hd1)' instead of the device nodes.

This is grub_1.99-21ubuntu3.1 on Precise. The md is raid1 with metadata
0.90 and the filesystem is ext4 with the flex_bg and uninit_bg features.

I used this trick a million times with all versions of grub and this is
the first time I observe such behavior. Any ideas?

-- 
 _ // Bernie Innocenti
 \X/  http://codewiz.org