[SOLVED] Re: Changing grub default boot order

[Jim Byrnes]

On 03/29/2013 02:00 PM, Colin Law wrote:
> On 29 March 2013 18:01, Jim Byrnes <jf_byrnes at comcast.net> wrote:
>> On 03/29/2013 12:40 PM, Jim Byrnes wrote:
>> <snip>
>>
>>
>>>>> 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.
>>>
>>
>> Changing both files worked.  The sdb1 line is highlighted and it boots to
>> 12.04.  The only side effect seems to be sda1 line no longer appears in the
>> menu.  I can curor up to the first kernal entry and boot to 10.04 so that's
>> not a problem.
>
> The reason I said that there may be confusion is that if the kernel in
> 12.04 is updated and it runs update-grub I am not sure that the right
> files will get updated for the new kernel to appear in the menu.
> Someone who knows more about how it all works would have to answer
> that.
>
> Colin

We will see the next time there is an update.  At least I will know what 
happened and should be able to deal with it.

Thanks,  Jim

>>
>> Thanks Colin for this solution.
>>
>> Regards,  Jim
>>
>>
>>>> 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
>>>
>>>
>>
>>
>>
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