Re: Grub2 almost does what I want

[Chris Murphy]

On Feb 2, 2013, at 1:18 PM, Richard Owlett <address@hidden> wrote:

> Using a newer version would be nice ---- BUT <grin>
> I'm installing from the Debian Squeeze 8 DVD set because I do not have high 
> speed internet available.
> Also it appears that Grub 2 is available only as source. I've not attempted 
> compile link load … for over 30 years.

It's strange to me that a September 2012 distribution is using a 2 year old 
version of GRUB. Anyway, if you want the current behavior you need to use a 
current version, I don't see a way around this.

> 
>>> 
>>> Do I have any options except following full manual edit of grub.cfg?
>>> [my reading of http://www.gnu.org/software/grub/manual/grub.html suggests I 
>>> don't.]
>> 
>> Directly editing the grub.cg isn't advised,
> 
> That was apparent from the abundant number of warnings on the issue.
> 
> 
> > it's better to make the changes in /etc/default/grub and then running 
> > grub-mkconfig -o /boot/grub/grub.cfg which reads the
> >  /etc/default/grub configuration, and produces a new grub.cfg from scratch.
> 
> So no semi-automatic tools to do what I specified :<

Yes it's called grub-mkconfig, which runs quite a large number of scripts to 
automate the location of all installed systems and create a grub.cfg that 
contains them. Some distributions disable this, and again there have been a LOT 
of changes in 2 years when it comes to OS discovery, and writing out the 
grub.cfg. I don't even know if Debian uses grub-mkconfig to find its other 
installs.

The way grub-mkconfig produces unique entries is with GRUB_DISTRIBUTOR= in 
/etc/default/grub. Again, it depends on the distribution setup of this, and it 
may be new in 2.00 and not in 1.98. In the case of Fedora 18 with the 2.00 
version of GRUB2 that line is:

GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"

So you need some modification of this for your distribution, so grub knows 
where to find system release info; and you'd need to give each installed system 
some unique derivative release name/number in order to get unique entries in 
the GRUB menu. I'm not sure how you'd expect GRUB to be capable of doing this 
automatically, it needs to be told.


Chris Murphy