Re: How many sectors for GRUB 2

[Andrey Borzenkov]

В Sat, 03 Nov 2012 23:37:41 +0100
Ulf Zibis <address@hidden> пишет:

> Am 03.11.2012 18:05, schrieb Andrey Borzenkov:
> > core.img is the part that is installed in MBR gap, but it does not
> > mean that it was this particular file. grub-install creates core.img
> > in /boot/grub and embeds it in the same run, but it is also
> > possible to directly use
> >
> > grub-mkimage -o /tmp/foo.img ...
> > grub-bios-setup -c /tmp/foo.img ...
> >
> > You wanted to be absolutely safe and sure. The only way to be is to
> > reinstall grub using grub-install.
> 
> You mean, after I would have shrinked th MBR gap?

No, before. Then you can be more or less sure it is the same file.

> That's the problem!
> What will happen, if the gap is too small?

grub-install will complaint and the only possibility will be to use
block list (i.e. point boot sector directly to core.img on filesystem).

> For that reason I *before* wanted to know how much space is needed.
> 

To be honest, I do not understand what your goal is.

> I tried:
> your bootinfoscript
> --> bootinfoscript.txt
> your findgrub
> --> findgrub.txt
> Ubuntu's boot_info_script from Ubuntu Software Center
> --> RESULTS.txt
> 
> As you can see in the attachment, none of these provided the size of
> the used bytes in MBR gap :-(
> 

Yes, you are right. Hmm ... may be something to add. But it is not that
trivial, it may also not be contiguous. Although I am not that sure how
useful this information really is.