Re: Configuring grub2 on a backup disk

[Jordan Uggla]

On Sun, Oct 16, 2011 at 5:46 PM, Jeffrey C. Dege <address@hidden> wrote:
>
> I'm running Ubuntu 10.04, and planning to upgrade. Before I do, though,
> I want to make sure my backup/restore processes work. My backups, of
> course, have been running since I first installed 10.04, but it's only a
> restore that can demonstrate that they have been running successfully.
>
> And I've found a problem. I don't know how to get grub2 configured
> correctly, on the restored disk.
>
> Currently, my running system is on /dev/sda, with /boot on /dev/sda1
> and / on /dev/mapper/desktop-root. (I'm using logical volumes.) This
> configuration has been running successfully for several years.
>
> My restore is on /dev/sdb, with /boot on /dev/sdb1 and /
> on /dev/mapper/desktop2-root.
>
> All of the files have been restored, and /etc/fstab has been edited, on
> the restored drive, to reflect the changed logical volume name.
>
> But I only have grub installed on /dev/sda, so /dev/sdb is not bootable.
>
> I'm not looking to do anything fancy. I'm not trying to dual boot, I
> just want to be able to boot from /dev/sdb, using /dev/sdb1 as /boot,
> and /dev/mapper/desktop2-root as /. In other words, I want to do
> to /dev/sdb exactly what running update-grub would do to /dev/sda, when
> I was booted off of /dev/sda.
>
> Any ideas?

Installing grub from one installed system to another install is
basically the same problem as installing from a liveCD. See:
https://help.ubuntu.com/community/Grub2#ChRoot

-- 
Jordan Uggla (Jordan_U on irc.freenode.net)