Changing grub default boot order

[Jim Byrnes]

On 03/29/2013 11:38 AM, Colin Law wrote:
> 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.
>

Yeah, my bad.  I completely overlooked that.  I tried the first one. I 
interrupted the boot process and was able to choose the second hard 
drive (12.04 on sdb1). Didn't work well as reported 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.

Something else I never thought of.  Not sure what confusion you are 
referring to here. Anyway I am going to try this before making anymore 
physical changes.

> 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.

The new Ubuntu is on /dev/sdb. Not having a real good idea of how all 
this works I worry a little abut this confusing my system.

> 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.


As luck would have it I just did a full backup yesterday.  I spent the 
first part of the week working with a the author of Backintime to get it 
to do a snapshot of my system.  There was nothing wrong with Backintime, 
I made a couple poor choices in what to backup.  I might add that he was 
very supportive and worked with me until I was able to get a good backup.


Regards,  JIm