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Re: Details behind a GRUB2 warning message?

Tom H wrote:
On Sun, Apr 6, 2014 at 1:22 AM, Richard Owlett <rowlett@cloud85.net> wrote:
Tom H wrote:

Let's assume that you have two Linux installations on sda, on sda1 and
sda2, and that grub is embedded in the mbr of sda for sda1 and in the
pbr/vbr of sda2 for sda2.

I have two distinct use cases
   1. one machine has multiple Debian installs {primary and logical
   2. one machine has WinXP on sda1 with multiple Debian installs on both
      primary and logical partitions with several logical partitions
      as NTFS

   1. I have no idea what "pbr/vbr" means
   2. I've not yet Googled 'chainloading of boot loaders'

If it's sda1's grub to which the bios hands over the boot process,
you'll be booting the installation on sda2 with one of these three,
"linux (hd0,msdos2)/boot/vmlinuz...", "configfile
(hd0,msdos2)/boot/grub/grub.cfg", "multiboot
(hd0,msdos2)/boot/grub/i386-pc/core.img", and none of them can be
affected by the block list issue.

My machine with only Debian *appears* well behaved.
My machine with both Windows and Debian gives me fits.

pbr/vbr is partition boot record/volume boot record (I don't know
which of them is more accurate/appropriate) and they refer to the boot
record of a partition as opposed to the boot record of a disk, the

I'm replying to you after 2-3 weeks so you might already have gogoled
chainloading but just in case:

If you're chainloading Linux, then the simplest way is to use one of
the above three methods.

If you're chainloading Windows, then you have to use "set root=(hd0,1)
; chainloader +1"; and you can use "drivemap..." or "parttool..." if
you need to fool the Windows bootloader into thinking that it's on the
first disk or the first partition respectively.

I haven't dual-booted Windows and Linux for a while, but I have, in
the past, when using Windows bootloader rather than grub to boot
WIndows, dd'd the Linux vbr to a file on "c:\" and created a
"c:\boot.ini" entry for Linux. With more recent versions of Windows
you'd have to use bcdedit to add a Linux entry but I've never done so,

FTR, if/when you upgrade your box(es), you should get EFI because it
makes dual-,triple-, ...-booting far simpler.

I'm not yet confident of my understanding of chainloading.
I've what is a viable workaround for *MY* habits/desires/quirks.
Basically the "active" GRUB is on its own partition and I manually edit that grub.cfg.

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