[solved] Wrong boot drive detected in GRUB?

[digitalamish]

This has been driving me crazy since I reinstalled. Originally I did an install of VidaLinux to get a flavor for Gentoo. Of course I got hooked, and eventually flushed the old system and rebuilt it using pure Gentoo. The problem I am having now is with drive detection and ordering.

Let me describe my hardware first. I have 6 drives hooked into my system using 2 Adaptec ATA cards (non-hardware RAID). Of the 6 drives, two are DVDRoms. I have each of the other 4 drives as primaries in their own IDE channel on the cards, and one on the MOBO primary IDE channel. A simple list of the system would look like this:
MOBO:
IDE-0 - HD1
IDE-1 - DVD1 DVD2
ATA Card1:
IDE-0 HD2
IDE-1 HD3
ATA Card2:
IDE-0 HD4

My intent is to software RAID these drives for a data directory only. Root and Boot will be standard partitions. Having everything on separate channels is probably overkill, but the cards were on sale and I figured what the heck.

Now for the problem. When I boot up using the Gentoo CD, it mount HD1 as /dev/hda. After the install, HD2 becomes /dev/hda. Even in Grub it recognized HD2 as hd0 and HD1 as hd3 (I hope that's confusing enough). When I installed VidaLinux it did recognize everything OK, and mapped it as I expected, but that install is long gone now. I just mention it because it did work at one point.

For the interium I have a workaround. I created matching partitions for boot and root on both HD1 and HD2. I have to 'dd' them to keep them in sync. This is nice because I was planning on keeping a partition for emergencies. If I ever lost a card or my primary drive, I could just alter GRUB to use the backup partition. Unfortunately unless I have both partitions now, my machine won't boot. GRUB appears to be in the bootsector of HD1, but as soon as GRUB starts up, it flips HD1 to hd3, and I had to change my boot line to refer to it.

Any GRUB guru's want to take a crack at this? It sounds like I might have a hardware boot ordering problem, however both VidaLinux and the Gentoo boot disk do see things as I expected.

[NeddySeagoon]

digitalamish,

Grub identifies your drives using BIOS order, so its not a grub problem.
I suspect the you have a setting in you BIOS that allows you to choose the boor order and its set to off board chip sets first, or something like that. If you can't find and fix the setting, grub allows yout to swap drives about.
This facility is normally used to get windows to boot from second or subsequent drives but it would solve your problem too.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[digitalamish]

Actually it was a GRUB problem, but my fault. I looked in the GRUB config files and found that the system.map file was incomplete. It was missing a couple of drives, and for some reason Grub was messing the order up because of it. I simply filled in the extra devices, and now it seems like it's back to normal.