"Mikkel L. Ellertson" <mikkel@xxxxxxxxxxxxxxxx> wrote:
Thufir wrote:
> pardon if I posted this before. I was working on grub last night.
> Win2k and Fedora 7 are on sda (hda) while FC3 is on sdb (hdb). The
> MBR on sda is being used, I believe.
>
> Which grub do I edit to get all OS's booting? I tried a few
> variations, mucking with the one in /boot/grub/... from FC3, but
> wasn't able to hit on the correct combination.
>
>
Chances are you will want to edit the one from F7. It depends on
what the last run of grub-install put on the MBR of the boot drive.
Mikkel
Chance's are that Mikkel is correct but it's whichever disk has an
"active partition" (bootable) and that will be found first given the
boot order set in the BIOS. Chances are that this is sda. Confirm your
BIOS boot order says to try sda first and that the partition containing
/boot on that drive is active. If you wanted to, you could have grub on
sdb controlling booting by adding the F7 and W2K partitions to it's
grub.conf and running grub-install under FC3 with the correct incantations.
The BIOS checks boot devices in the order specified through the BIOS
setup. When it finds the first device that meets the criteria given
through setup, the BIOS reads, loads and then executes some (fairly
trivial) code on the same sector that holds the partition table. This
code reads the partition table and looks for an active partition. The
MBR of the active partition is loaded and executed. This is where grub
gets installed so this will hopefully be grub which then finds your
grub.conf and does whatever you have specified.
As an example, the boot device on my server (CentOS 4.5) is /md3 (RAID 1
mirror) that consists of /dev/hde and /dev/hdg but I've told the BIOS to
use those drives instead of /dev/hda.
Cheers,
Dave
--
Politics, n. Strife of interests masquerading as a contest of principles.
-- Ambrose Bierce
