[Fwd: Bug#532202: grub-pc: behaves strange in virtualbox with a disk > 2 TB]

[Fwd: Bug#532202: grub-pc: behaves strange in virtualbox with a disk > 2 TB]

[Felix Zielcke]

Seems like 64bit filesystem/disk support isn't that well tested
(Ok doestn't surprise me who has a > 2 Tib disk :))

-------- Weitergeleitete Nachricht --------
> Von: Marc Haber <mh+debian-bugs@zugschlus.de>
> Reply-to: Marc Haber <mh+debian-bugs@zugschlus.de>,
> 532202@bugs.debian.org
> An: Debian Bug Tracking System <submit@bugs.debian.org>
> Betreff: Bug#532202: grub-pc: behaves strange in virtualbox with a
> disk > 2 TB
> Datum: Sun, 07 Jun 2009 14:51:23 +0200
> 
> Package: grub-pc
> Version: 1.96+20090603-1
> Severity: normal
> 
> Hi,
> 
> I am trying to use grub2 to loopback boot an grml .iso file which is
> stored on a 1000 cylinder partition on a 4 TB hard disk in virtualbox.
> my grub configuration is the second one visible in
> http://blog.zugschlus.de/archives/825-grml-als-eigenes-Rescuesystem.html.
> 
> This fails in two "interesting" ways:
> 
> When I simply hit enter on the grub menu, I get "you need to load the
> kernel first", and when I hit "e" afterwards, I only see the "loopback
> oop (hd0,1)/grml/grml-small_2009.05.iso" line, neither the linux nor
> the initrd line.
> 
> When I directly go into "e" before actually trying to boot, I see the
> full configuration, and Ctrl-X gets me to an "invalid magic number"
> error message.
> 
> When I try the same (identically configured grub2 on a 1000 cylinder
> partition) on a 1 TB hard disk, everything is just fine.
> 
> I do not know whether this is an issue with the virtualbox "BIOS" or
> with grub2, and I do not have any real hardware with a disk that big,
> but grub 2's behavior depending on whether I try to boot straight or
> try to edit things first is interesting.
> 
> The virtual hard disk .vdi file which can be used to reproduce this
> with virtualbox-ose 2.2.4 from Unstable is 1.2 G uncompressed and 92 M
> bz2 compressed, so it would be possible to upload the compressed image
> to some server if you want to see it yourself.
> 
> Greetings
> Marc
> 
> -- System Information:
> Debian Release: squeeze/sid
>   APT prefers unstable
>   APT policy: (500, 'unstable')
> Architecture: i386 (i686)
> 
> Kernel: Linux 2.6.29.4-zgsrv20080 (SMP w/1 CPU core; PREEMPT)
> Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
> Shell: /bin/sh linked to /bin/bash
> 
> 
> 
> _______________________________________________
> Pkg-grub-devel mailing list
> Pkg-grub-devel@lists.alioth.debian.org
> http://lists.alioth.debian.org/mailman/listinfo/pkg-grub-devel


-- 
Felix Zielcke

Re: [Fwd: Bug#532202: grub-pc: behaves strange in virtualbox with a disk > 2 TB]

[Samuel Thibault]

Hello,

This is most probably a bug of the BIOS.  I had pushed to bochs' BIOS
a patch to implement LBA48 so as to overcome the LBA28 limitation
(2^28*512 = 128GB), but it still has a 2^32 sectors limitation as all
computations are done with 32bit integers, that's 2TB...

Samuel

Re: [Fwd: Bug#532202: grub-pc: behaves strange in virtualbox with a disk > 2 TB]

[Robert Millan]

On Fri, Jul 24, 2009 at 01:57:45PM +0200, Samuel Thibault wrote:
> Hello,
> 
> This is most probably a bug of the BIOS.  I had pushed to bochs' BIOS
> a patch to implement LBA48 so as to overcome the LBA28 limitation
> (2^28*512 = 128GB), but it still has a 2^32 sectors limitation as all
> computations are done with 32bit integers, that's 2TB...

Actually, I fixed that a while ago.  Recent bochsbios should support 48-bit
offsets.

But not all proprietary BIOSes do, of course.

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."