Grub-Install to New md-disk

[Tim Johnston]

I've got some new hard drives, that I want to use with linux software 
raid as raid-1 arrays. System is Debain 6.0.0 (squeeze). Grub is 
1.98+20100804-14. I'm booting off Debian 6.0.0 live CD,  partitioned the 
new disks, created the arrays, created filesystem on them, mounted them, 
and copied from old drives onto new arrays.

But I can't get them to boot.

I've mounted /dev/md0 on /newdisk, then run:

grub-install --root-directory=/newdisk --recheck /dev/sda

This installs grub on the disk OK. But it doesn't create a working 
/boot/grub/grub.cfg. This seems to be an oversight. update-grub doesn't 
work in this situation, even if 'chroot /newdisk'.

So when booting, I end up with grub command prompt>

I've tried then booting manually with:

set prefix=(md/0)/boot/grub
set root=(md/0)
insmod linux
linux /boot/vmlinuz-2.6.38 root=/dev/md0 ro
initrd /boot/initrd.img-2.6.38
boot

This starts to boot, but then drops to busybox prompt with message that 
it can't mount the arrays (/dev/md0, being the root partition). But I've 
got raid-1 support compiled into the kernel (rather than as module). So 
I don't know what the problem is.

Much obliged if anyone can suggest something.

regards, Tim