Triple boot:XP,ubuntu&FC5 grub failed

Jim Cornette fc-cornette at insight.rr.com
Thu Sep 7 22:04:12 UTC 2006


Mike McCarty wrote:

> The BIOS does NOT search the partition table for an active partition.
> It is the code in the MBR which does that. All the BIOS looks for
> is the first physical sector on the physical volume having the BOOT
> RECORD signature (AA55) in the last two bytes. The BIOS accesses the
> disc in a physical manner (LBA translation aside). It knows nothing
> about partitions. Indeed, there are more than one way of partitioning
> discs, and the "traditional" method is not the only one. Anyway, if
> the BIOS finds the BR signature in the first physical sector, then it
> simply loads it to 0000:7C00 (IIRC) and jumps to it. [NB: The processors
> all reset to REAL mode, so this is not a selector address, but a
> segmented address.]
> 
> Mike

So if I want to install grub onto partition 2 of my first drive and have 
no Grub installed into the MBR, the BIOS will not start loading whatever 
is in the first sector of my second partition?
I have not tried to load grub into a partition and then make the 
partition active. I thought that I read that someone else was loading 
grub from a partition.
I changed the active partition for the other OS and the OS which was on 
the active partition booted. When I changed the active partition to the 
other "other" OS, the secondary OS booted. I assumed that grub loaded in 
a similar way as the other OS to Load the Linux OS with the information 
grub puts into the selected partition.

I'm confused a bit on what grub is capable of. I'm curious enough to 
experiment on a computer. I want to try to run two different Linux 
distributions and be able to toggle the active partition in my 
experimenting. (Grub installed in the selected partition, no grub in the 
MBR)

Jim


-- 
Many receive advice, few profit by it.
		-- Publilius Syrus




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