Grub 2 information

[Colin Law]

On 2 April 2010 04:28, Goh Lip <g.lip at gmx.com> wrote:
> On 04/02/2010 05:58 AM, Karl F. Larsen wrote:
>
>>       I am now booted automatically into Ubuntu version 8.04 as I
>> desired. I had to replace the 0 with 21 to get here. You Must
>> count every line of the boot menu which includes kernel lines.
>> This means every time I get a new kernel for Lucid it will
>> break this setup! So it is not a good solution. But it is at
>> least a solution! now to improve on it, if possible.

Karl, note that you can also put a string in GRUB_DEFAULT (see the
previously mentioned wiki link) where the string is _exactly_ the
complete string for the one you want to default to that you see on the
menu when you boot.  If you use this then a new kernel in Lucid will
not cause a problem.  Of course a new kernel in karmic (if that is
what you defaulting to) will cause it's name to change so you would
have to change GRUB_DEFAULT then.

>
> Can you recall how that's done for grub-legacy? Did it not also break
> this setup? How was grub-legacy better in this respect? Not by having to
> go to /etc/default/grub? So you just change the menu.lst and 'rechange'
> every time you've got a new kernel?
>
> So, just go change the grub.cfg and 'rechange' every time time you get a
> new kernel! But, nooooo, because it advises against that. Why is the
> warning there? To tell us that the changes made just at grub.cfg won't
> stick for next grub-update. But I am sure you know that already.
>
> Furthermore, can you think of a better way the grub developers can do
> this, either for grub-legacy or grub2? For example, can the system
> magically 'know' you want 8.04 to be first boot and go about doing this?
> What happens when you want the 2nd older kernel at 8.04 to be first boot
> instead? Can it read your mind?

Yes, I can think of an improvement.  If a regular expression could be
set for GRUB_DEFAULT, and it defaulted to the first one on the menu
that matched, then one could use that to select the first karmic entry
for example.  I guess this would be a trivial change in grub2.  I
agree this would not let you select the second older kernel of 8.04
but that is not a common requirement so I am not sure it matters if
you have to change the default to do this.

Colin