Re: Where does GRUB reside ?

On Sun, 01 Jun 2008 17:22:21 -0700, Emerald Saint wrote:

I had a Windows Vistsa system that was broken, and I had also erased the
boot code from the MBR - but not the partition table. The boot code is
proprietary to HP Pavilion. There was no other boot code I could write
to the MBR that would get so much as an error message out of the broken
Vista installation. And I had permanently lost the proprietary code.

I installed Ubuntu on another partition. Ubuntu worked fine, but I
later erased the Ubuntu partition. Then I got ahold of a CD that could
possibly repair my broken Vista system. I ran the CD and was able to
get the Vista up and running again. I thought I might have gotten the
proprietary boot code back, so I looked at it with a disk editor and
found it now has GRUB boot code in the MBR. If I hadn't put Ubuntu on
the computer Vista would still be inaccessible !!!

Too cool. I did some research and found there are ways to get great
dual boot capability using GRUB. Now I am interested to know where GRUB
resides. With my disk editor I see there is about 18 sectors of GRUB in
the first track (head 0) on the hard drive. But there is some more
stuff on the second track (head 1) that looks like it is also GRUB.
With all that real estate it seems like GRUB probably doesn't use the
boot flag in the partition table to pick the partition for booting.

I do a lot of tinkering with the drive sometimes for backing up data and
for copying partitions and just for experimentation. I am interested to
know what areas of the drive are used by GRUB - so I copy them when
necessary and so I don't accidentally over write or erase part of GRUB.

Grub, The GRand Unified Bootloader, is primarily installed on the MBR of
the first hard drive, but can be installed on the boot sector of any
partition when circumstances require it. As you've learned, grub will
also boot other OSes.

Linux and grub do not need nor do they require the boot flag to be set on
any partition to boot it. That's a Windows thing.

This link may help further:

http://www.gnu.org/software/grub/

Also, if you have Linux running, typing 'info grub' in a terminal or
shell will bring up grub's user manual.

Stef
.

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