GRUB badly broken during upgrade

[Kevin O'Gorman]

On Mon, Oct 8, 2012 at 3:03 PM, Kevin O'Gorman <kogorman at gmail.com> wrote:
> 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.

I ditched the generic kernels and rebooted.  Boot was normal (of
course I had to select line 6).  Lines 8-11 are still there, which
makes no sense because the kernels they refer to are gone.  I have no
idea how to fix this, but it's not important.

What would be much better would be to make lines 1&2 functional.
Then it would be nice to swap the contents of 1&2 with 6&7.

-- 
Kevin O'Gorman

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