Bug#542424: grub-setup: warn: Embedding is not possible.

[Felix Zielcke]

Am Mittwoch, den 19.08.2009, 22:57 +0200 schrieb Marc Haber:
> Hi,
> 
> On Wed, Aug 19, 2009 at 08:27:53PM +0200, Felix Zielcke wrote:
> > Am Mittwoch, den 19.08.2009, 17:25 +0200 schrieb Marc Haber:
> > > When I try updating an existing Debian sid system to grub-pc, I get
> > > the following mesages:
> > > 
> > > Setting up grub-pc (1.96+20090808-1) ...
> > > grub-setup: warn: This msdos-style partition label has no post-MBR gap; embedding won't be possible!
> > > grub-setup: warn: Embedding is not possible.  GRUB can only be installed in this setup by using blocklists.  However, blocklists are UNRELIABLE and its use is discouraged.
> > > 
> > > The disk was partitioned with
> > > echo -e "0,$P1SIZE,0x83\n,,0x8e\n;" | sfdisk -uM --no-reread $DEVICE
> > > with P1SIZE most probably being 400.
> > > 
> > > This is the resulting partition table:
> > > 
> > > $ sudo fdisk -lu /dev/sda
> > > 
> > > Disk /dev/sda: 4294 MB, 4294967296 bytes
> > > 255 heads, 63 sectors/track, 522 cylinders, total 8388608 sectors
> > > Units = sectors of 1 * 512 = 512 bytes
> > > Disk identifier: 0x00000000
> > > 
> > >    Device Boot      Start         End      Blocks   Id  System
> > > /dev/sda1               1      819314      409657   83  Linux
> > > /dev/sda2          819315     8385929     3783307+  8e  Linux LVM
> > > 
> > > 
> > > Is grub misdiagnosing, or are all my existing systems prone to get
> > > unstable when I have to use blocklists to convert to grub2 in the
> > > future?
> > > 
> > 
> > Hi Marc,
> > 
> > well the first partition starts at sector 1, so there is absolutely no
> > space between MBR and first partition to embed.
> 
> So sfdisk is essentially incompatible to grub 2?

Just make sure the first partition starts at sector 63 like any normal
partioning tool does.
I don't know sfdisk but I doubt it wouldn't be possible with it, else
you couldn't even create a proper 2nd partition probable.

> > grub-legacy should tell you too that it can't embed stage1.5 just not
> > that visible.
> 
> It has however never shown any unreliability in years on hundreds of
> hosts. grub 2 says it won't function properly.

With grub-legacy it's exactly the same.
We just decided to make it more clear in grub2 that blocklists aren't
that great.