Changing grub default boot order

[Colin Law]

On 29 March 2013 16:27, Jim Byrnes <jf_byrnes at comcast.net> wrote:
> On 03/29/2013 03:34 AM, Colin Law wrote:
>>
>> On 28 March 2013 23:25, Jim Byrnes <jf_byrnes at comcast.net> wrote:
>>>
>>> On 03/28/2013 03:14 PM, Colin Law wrote:
>>>>
>>>>
>>>> On 28 March 2013 17:45, Jim Byrnes <jf_byrnes at comcast.net> wrote:
>>>>>
>>>>>
>>>>> On 03/28/2013 12:12 PM, Colin Law wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 28 March 2013 15:47, Jim Byrnes <jf_byrnes at comcast.net> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> I upgraded from 10.04 to 12.04 by installing 12.04 on a different
>>>>>>> hard
>>>>>>> drive
>>>>>>> and dual booting.  Now I would like to make 12.04 (sdb) the default.
>>>>>>> This
>>>>>>> link [1] suggests using grub-customizer [2]. Does anyone have any
>>>>>>> experience
>>>>>>> with this app?
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> How did you manage to install 12.04 and not end up with it as the
>>>>>> default?  The question is relevant because you might be best to
>>>>>> reinstall grub from 12.04.
>>>>>>
>>>>>> Colin
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> I put a new hard drive in the machine and disconnected the one with
>>>>> 10.04
>>>>> on
>>>>> it.  I then installed 12.04 on the new drive.  I wanted to keep the
>>>>> info
>>>>> on
>>>>> 10.04 available.  I had planned on using a drive caddy. At this point I
>>>>> had
>>>>> completely forgotten about dual-boot.  Once I had both hard drives
>>>>> hooked
>>>>> up
>>>>> this is what I ended up with.  Maybe there was a way to have 12.04 as
>>>>> the
>>>>> default but I didn't realize exactly what would happen.
>>>>
>>>>
>>>>
>>>> I am going to suggest an alternative solution.  The problem, I think,
>>>> is that it is booting off the old disk.  I suggest changing the boot
>>>> sequence so that it boots off the 12.04 disk.  If you find that you do
>>>> not then get the boot option of 10.04 then run sudo update-grub.
>>>>
>>>> Colin
>>>>
>>>
>>> Yes it boots off of the original hard drive. 10.04 is on it as sda and it
>>> sits at the top of the grub menu.
>>>
>>> Are you suggesting that I fiddle with the bios.  I don't know if there is
>>> an
>>> option to select which hard drive to boot from. I had thought about it
>>> but
>>> never followed up.
>>
>>
>> Yes, adjust it in the bios.  If you have two drives I think you should
>> be able to select which one to boot from  Alternatively swap over the
>> two drive connections so that (I think) sda and sdb will swap, though
>> not absolutely certain whether that will achieve the same result.
>
> I just tried that and it did not work.  A lot of text scrolled by and I
> ended up at a console.  I thought "oh crap" what did I do now, but a reboot
> got me back to normal.

Tried what?  There are two suggestions in the paragraph above.

>
> I also found some info on the web about changing GRUB_DEFAULT=. I tried
> changing it to GRUB_DEFAULT=14. (sdb1 is on line 15) and I tried changing it
> to "Ubuntu, with Linux 3.2.0-39 generic (on /dev/sdb1)". Both of these were
> suggestions I found on line but neither worked.

You may be changing it on the wrong file.  Remember there will be one
on each disk.  I think as you have it you probably have to boot into
the old ubuntu (so the default boot) and change it there.  this is
going to cause continuous confusion however, hence my suggestion to
boot off the second disk by one means or another.

Alternatively, you could boot into the new Ubuntu and, assuming that
it is booting of /dev/sda, then run
sudo grub-install /dev/sda
and
sudo update-grub

That should re-install grub with the new one as the default.

You have backed up everything important on both disks before doing any
of this haven't you?  There is always some risk involved in this sort
of activity.

Colin

>
>
> Regards,  Jim
>
>
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