在 Ubuntu 12.04 上进行 apt-get 升级后如何配置 GRUB 加载程序

Question

我有一个装有 Ubuntu 12.04 的盒子，并且刚刚进行了 apt-get 升级。我看到了一个对话框来更新我的 GRUB 引导加载程序，但显示以下消息：

The GRUB boot loader was previously installed to a disk that is no longer present,
or whose unique identifier has changed for some reason. It is important to make sure that the
installed GRUB core image stays in sync with GRUB modules and grub.cfg. Please check
again to make sure that GRUB is written to the appropriate boot devices.

If you're unsure which drive is designated as boot drive by your BIOS, it is often 
a good idea to install GRUB to all of them.

Note: it is possible to install GRUB to partition boot records as well, and some
appropriate partitions are offered here. However, this forces GRUB to use the blocklist
mechanism, which makes it less reliable, and therefore is not recommended.

GRUB install devices:
[ ] /dev/sda (3000592 MB; ST3000DM001-9YN166)
[ ] /dev/sdb (3000592 MB; ST3000DM001-9YN166)
[ ] /dev/md1 (536 MB; rescue:1)
[ ] /dev/md2 (1099510 MB; rescue:2)

我担心选择错误的选项会使我的盒子无法启动。我无法物理访问它，因为它是云中的一个盒子。请指教！

编辑：

这是我的 /etc/fstab：

proc /proc proc defaults 0 0
/dev/md/0 none swap sw 0 0
/dev/md/1 /boot ext3 defaults 0 0
/dev/md/2 / ext4 defaults 0 0
/dev/md/3 /home ext4 defaults 0 0

这是我的 df -h：

Filesystem      Size  Used Avail Use% Mounted on
/dev/md2       1016G  127G  838G  14% /
udev             16G  4.0K   16G   1% /dev
tmpfs           6.3G  768K  6.3G   1% /run
none            5.0M     0  5.0M   0% /run/lock
none             16G     0   16G   0% /run/shm
/dev/md1        496M   44M  427M  10% /boot
/dev/md3        1.7T  368G  1.3T  23% /home

Answer 1

仅供参考：我顺利通过了。在我的设置中，我在/dev/sda和上都安装了 GRUB /dev/sdb，并且运行良好。