さらにgrubのメッセージが変わる。

$ sudo grub-install --no-floppy /dev/sda3 --force
grub-setup: warn: Attempting to install GRUB to a partition instead of the MBR.  This is a BAD idea.
grub-setup: warn: Embedding is not possible.  GRUB can only be installed in this setup by using blocklists.  However, blocklists are UNRELIABLE and its use is discouraged.
Installation finished. No error reported.
$ echo $?
0

RCが0なのでちゃんとできてそうなんだが、今までと正常実行時のメッセージが変わるのは紛らわしいのでほんと止めてほしいなぁ。

update-grub2は今までどおり。

$ sudo update-grub2
Generating grub.cfg ...
Found Debian background: moreblue-orbit-grub.png
Found linux image: /boot/vmlinuz-2.6.31.3
Found initrd image: /boot/initrd.img-2.6.31.3
Found linux image: /boot/vmlinuz-2.6.31
Found initrd image: /boot/initrd.img-2.6.31
Found linux image: /boot/vmlinuz-2.6.30.2
Found initrd image: /boot/initrd.img-2.6.30.2
Found linux image: /boot/vmlinuz-2.6.26-2-amd64
Found initrd image: /boot/initrd.img-2.6.26-2-amd64
done