grub error 22. Bad partition table? [solved]

[John DeDourek]

Duncan Lithgow wrote:

> I'd better mark this thread solved...
> 
> 
>> That suggests to me that it's probably safest to put grub in hda1 or 
>> so, and mark that partition bootable.
> 
> 
> That's the default isn't it? Paul said that MBR is in the first part of 
> hda1 - and because I'm also running windows it _has_ to be marked 
> bootable (or somewhere before 1024 has to)
> 
> Thanks again for the help
> 
> Duncan
> 
Just a clarification.  There is a boot block at the beginning of
disk (BEFORE the first partition) and a boot block at the beginning
of every partition.  "MBR" refers to the boot block at the beginning
of the disk.

Now, something that I'm less sure of.  If you put grub into the MBR
(means code in the MBR and the 1.5 stage in the following sectors)
then it can boot any partition, marked "bootable" or not.

If you install grub in some other partition (technically the boot
block of that partition with stage 1.5 in the following sectors)
then the code executed first will be whatever is installed in MBR.
If that code is installed by windows, then I believe that it loads
the code from the boot block of whichever partition is marked
bootable.  That would have to be the partition with grub in the
boot block if you want to bring up grub.

Now if you want that grub to chain load windows, I think (but am
not sure) that you need to change which partition is bootable
(using grub commands in  grub.conf) to mark the windows partition
bootable before you chain to its boot loader.

Perhaps someone more knowledgeable about grub could confirm or
correct this latter comment.