Re: Details behind a GRUB2 warning message?

[Richard Owlett <rowlett@cloud85.net>]

Tom H wrote:
> On Fri, Apr 4, 2014 at 9:59 AM, Richard Owlett <rowlett@cloud85.net> wrote:
> > Thank you. My individual use case appears to be adequately safe, perhaps
> > more due to good luck than good management. However a couple of side
> > comments plus something I read somewhere hints at a more elegant solution.
> > Will have to some experiments.
>
> 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.

Preamble:
I was recently reminded that " [my] ignorance is archived. :) "

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

For the record ;/
  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.
I have more reading to do before asking intelligent (aka 
answerable) questions.

P.S. Having written one test procedure and one manual (decades 
ago) I *DO* believe in reading documentation  ;)