Dual-booting with GRUB, md, and hardware RAID
I am having a problem with the Debian installer whereby I can't get my
machine to find the GRUB loader. This is probably a problem with my
motherboard (asus m2n sli deluxe), and not so much the installer per se,
but please let me know if you see away around this.
I've got four drives in my machine, sdc and sdd are a "hardware" RAID
via the nvidia controller running vista 64. sda and sdb are laid out
for a software raid via md like this:
sda1, sdb1: ext3 at /boot
sda2, sdb2: lvm on raid for everything else (swap included)
At the end of the install process, GRUB gets installed into the MBR and
the installer correctly ids Vista's presence, but on reboot, I end up
right back in Vista. I checked out my BIOS and RAID options, and here's
a summary of the limitations:
- BIOS only allows for me to pick between things like "Hard drives,"
"CDROM," "Floppy," and order they're tried in.
- RAID setup only allows me to pick which of the currently active arrays
to boot from. Since I'm using md, I didn't create an array for sda/sdb,
and therefore only the windows array is available and is always marked
for boot.
- when in windows and the hardware raid is active, it only sees arrayed
disks. sda and sdb don't even exist to device manager once booted; only
the second array exists.
I've tried the following:
1) originally my windows drives were sda and sdb, I've swapped them in
the hope of being able to boot GRUB when they were first, but it appears
that the RAID controller's boot priority takes precedence.
2) I've tried making a second array out of sda and sdb after the debian
installer finished and then marking it for boot, but I just get a BIOS
message about not finding the boot loader.
3) if all of the arrays are deleted, it just hangs on a black screen.
I'm guessing this is trying sda and not getting anywhere.
4) I've booted into a Knoppix cd and then run 'grub-install
--root-directory=/mnt/sda1 /dev/sda' in the hopes that would hit the MDR
of the first drive, but this doesn't change #3.
5) I've tried using EasyBCD in windows to get the vista boot loader to
chain to GRUB, but it doesn't seem to find it. I'm guessing this has to
do with the "windows only sees arrays" observation above.
Sounds to me like I would optimally like to be able to make the boot
process aware of the nvidia raid and then use GRUB to install to that
(isn't this a bad idea generally? Guides I've read say to avoid the
vendor-specific raid drivers and just stick with pure md). Alternately,
maybe there's a way to get Knoppix to install to the md device instead
of sda or sdb, and somehow get the BIOS to play nice and boot there -
wherein the problem is getting the motherboard to let me choose which
specific device to boot from.
Any other suggestions for how to solve this would be greatly
appreciated. I'm pretty new to Linux and RAID stuff, so I apologize in
advance for my naivete and need for specifics.
Thanks,
Michael
Reply to: