GRUB badly broken during upgrade

[Kevin O'Gorman]

This is after the reboot....

On Mon, Oct 8, 2012 at 1:22 PM, Tom H <tomh0665 at gmail.com> wrote:
> On Sun, Oct 7, 2012 at 1:38 PM, Kevin O'Gorman <kogorman at gmail.com> wrote:
>> On Sun, Oct 7, 2012 at 10:37 AM, Kevin O'Gorman <kogorman at gmail.com> wrote:
>>> On Sat, Oct 6, 2012 at 6:35 AM, Tom H <tomh0665 at gmail.com> wrote:
>>>> On Fri, Oct 5, 2012 at 7:01 PM, Kevin O'Gorman <kogorman at gmail.com> wrote:
>>>>>
>>>>> When I had just installed Xubuntu, the grub menu would show its
>>>>> 3.0.0-26 kernel at the first two lines, followed by memtest, then the
>>>>> Ubuntu 2.6.x kernels with an explicit root for Ubuntu. The 3.0.0
>>>>> lines would boot to Xubuntu, and the 2.6 lines to Ubuntu.
>>>>
>>>> Please run bootinfoscript [1] and upload the results because I (for
>>>> one) don't understand your description of your setup.
>>>>
>>>> 1. http://sourceforge.net/projects/bootinfoscript/files/bootinfoscript/
>>>
>>> Nice script.
>>>
>>> When I ran this, the apparent state of things was that I had a working
>>> Xubuntu 12.04.1 on /dev/sdb2, and an unbootable Ubuntu 11.10 on
>>> /dev/sdb7.
>>>
>>> This brokenness of the 11.10 does not particularly trouble me, since I
>>> was migrating towards Xubuntu anyway, and I can mount the older setup
>>> to retrieve what I need.  At the moment, I'm reluctant to try to
>>> rectify it for fear of losing the bootability of the Xubuntu.  I've
>>> had to reinstall it once already, and I'd rather not do it again.
>>
>> Oh, and the results of the bootinfo script are attached.
>
> What a mess!
>
> The "grub.cfg" in the sdb2 "/boot" (Xubuntu 12.04) points to incorrect
> "/boot" and "/" because it's pointing at a non-existent UUID
> ("ab460680-9e94-4898-8b46-f28d1615bf7b").
>
> It points at the 3.2 kernel on "ab460680-9e94-4898-8b46-f28d1615bf7b"
> (the non-existent one) and the 3.0 and 2.6 kernels on sdb7.
>
> The "grub.cfg" in the sdb7 "/boot" (Ubuntu 11.10) points to "/boot"
> and "/" on sdb7 but considers sdb to be sda since it calls it hd0.
>
> It points at the the 3.0 and 2.6 kernels on sdb7 using the correct
> UUID ("f71d3572-440d-4c3c-98b0-be3d3227d55a") and the 3.2 kernel on
> sdb2.
>
> "core.img" on sda and sdc is pointing at sdb7 via embedding a file
> into "core.img" to set the UUID of "/boot" and the corresponding
> prefix. I don't see how this could possibly have been done by the
> automated installation tools. You must've created the "core.img" on
> sda and sdc and embedded a file into it with "-c".
>
> "core.img" on sdb points at "/boot/grub/" on sdb2.
>
> You said in one of your posts that you get a "grub rescue" prompt.
>
> What's the result of "ls" and "set" at that prompt? We should be able
> to walk you through boting from that prompt.

The grub rescue prompt stopped happening when I reinstalled Xubuntu
(from scratch).

The grub menu shows 11 items.  Kernels are in normal/rescue pairs
1,2) Unusable boot to a 3.0.0 kernel.  the "linux" line explicitly has
root=/dev/sda7 which may explain its being dead; the drive with a
partition 7 more frequently comes up as sdb, but has been sda in the
past.  3.0.0 is an appropriate kernel for Ubuntu 11.10, which is
what's on sdb7.
3) "Previous versions" legend line
4,5) memtest.  This operates normally
6,7) 3.2.0-31-pae kernel.  root=UUID of the sdb2 partition.  That's
what i'm running now.  free(1) shows 8GB ram.
8.9) as 6&7, but it's the generic kernel which only sees 3 GB ram
10,11) as 8&9 (generic) an older kernel version.

I think 1&2 may be fixable if I can get them to use the UUID.  In GRUB
1 I could do this manually.  I don't know how to do it in GNU GRUB.
I'm going to ditch 8-11 as useless.




-- 
Kevin O'Gorman

programmer, n. an organism that transmutes caffeine into software.