The simplest workaround I could come up with for getting grub-installer to succeed with RAID devices on Natty was:
d-i grub-installer/skip boolean true d-i lilo-installer/skip boolean true
d-i preseed/late_command string ln -s ../md0 /dev/md/0; grub-installer /target
The simplest workaround I could come up with for getting grub-installer to succeed with RAID devices on Natty was:
d-i grub-installer/skip boolean true
d-i lilo-installer/skip boolean true
d-i preseed/ late_command string ln -s ../md0 /dev/md/0; grub-installer /target