newbie posting - could use some help with grub

robc · n00b Joined: 06 Aug 2002 Posts: 3

I was given a copy of gentoo by a friend and I've been working for the past few days to get it running. I've followed the gentoo install documents I pulled off the gentoo.org site and after getting everything setup I thought I was in the clear. However, when I try to boot the system I just get the words "GRUB GRUB GRUB GRUB" all the way across the screen from top to bottom and the hard drive is going nuts. I have no idea what's going on and neither does the guy who gave me the copy of gentoo. Here's some info about the system and how I've been working on it.

AMD 1400 Mhz Athlon, 256 MB RAM, 2 HDD's (one 40 GB with Windows 98 SE - Master on IDE1), and one 27 GB with Gentoo (Slave on IDE1). When I set up the slave drive (27 GB) using fdisk it came up as hdb, so in /etc/fstab I have listed /hdb1 as the boot (ext2), /hdb5 as the swap (swap), and /hdb6 as the root (ext3). When I setup grub's menu.lst, I have root as hd1,0 and I also setup grub on hd1,0 (boot partition of hdb).

Now when I want to attempt to boot the slave drive I do have to swap them in the bios to tell it to boot from that drive instead of the master. Otherwise it just boots into Win98SE. But, when I swap them all I get is the GRUB GRUB GRUB lines that fill up my screen. I have no clue what's going on. BTW, I have not remapped hd1 as hd0 and vice-versa. I didn't think I'd have to do that since hd0 is the win98 drive and hd1 is the gentoo drive. Does swapping them in the bios of which to boot to make grub think that the slave drive is now hd0 instead of hd1, even though according to the ide controller it's still the slave?

Any help would be appreciated as I'd love to get this working, but I'm just getting frustrated with it. If you need more info just ask and if I can't remember what I put for certain values I'll let you know this evening.
_________________
- Rob

BonezTheGoon · Posted: Tue Aug 06, 2002 2:28 pm Post subject:

I think you hit the nail on the head already. I have seen this strange behavior on one of my systems. Grub is really quite freaky about hard drive numbers. I have an Abit BE6-II which has an additional IDE controller from HighPoint and had my large disk (10GB) on the Highpoint controller and had a small (1.2GB) disk on my onboard intel 440BX controller. Turns out the small 1.2GB drive died, so since I had nothing for Gentoo on it anyway, I yanked it. Long story short the way Grub counts drives (hd1 vs. hd0) is not anywhere near how you address them in linux (/dev/hdxx). So I am sure that for whatever bizarre reason Grub is now considering your slave drive to be hd0 since the BIOS is booting directly to it. I would simply install Grub on your MBR on your master drive. I have done this many times and it will not hurt your existing OS (Win98SE)--if at some point you remove Gentoo and you need to clean out your MBR to boot into Windows98 without grub you will need to use a Win98 boot disk and fdisk the mbr. If you were using WinNT or Win2000/XP you could use this thread to get you going, maybe still worth a read anyway though.

Good luck!

Regards,
BonezTheGoon

robc · n00b Joined: 06 Aug 2002 Posts: 3

Could I just do the map (hd0) (hd1) map (hd1) (hd0) lines in the menu.lst file to do the same? I'm not real comfortable with hacking on the MBR of the Windows drive yet (call me gunshy, but I'm not a linux convert - yet).

If I can't get that to work, (and I get a little more brave about hacking up the MBR of the windows drive), how do I go about loading grub on there? I thought it was only a Linux thing. I can't run "emerge grub" from a DOS prompt as it would have no clue what to do. I've tried finding downloads for GRUB on the web and all it's been listing is downloads of redhat or other Linux OS, but nothing with just grub binaries or installation files.
_________________
- Rob

mwahl · n00b Joined: 04 Aug 2002 Posts: 35

GRUB also caused me some problems.
Just a warning - the map feature of GRUB isn't working in some configurations. I have 2 IDE drives and 1 SCSI drive with the BIOS booting from the first IDE drive. Win9x is sitting on the SCSI disk and therefore I had to exchange hd0 with hd2, but I couldn't persuade GRUB to handle it.

Tried Lilo and everything worked fine...

Check some of the GRUB HOWTOs, I remember reading something about a screen full of GRUBs. It's an error code ...

BonezTheGoon · Posted: Tue Aug 06, 2002 3:25 pm Post subject:

If you do want to try and install grub into the MBR of your Win98SE disk simply follow the directions outlined in the Build Document you used earlier but this time specify HD0 instead of HD1.

Regards,
BonezTheGoon

robc · n00b Joined: 06 Aug 2002 Posts: 3

It won't have any trouble writing to a FAT32 partition? Or does that not matter?

Sorry if this is a stupid question, but like I said at the beginning - I'm new at this.
_________________
- Rob

BonezTheGoon · Posted: Tue Aug 06, 2002 4:20 pm Post subject:

The MBR is a "special" zone on your hard disk that is not really a part of the partition table, therefore it is not a fat32 file system. You will have no problems installing it there from Linux. You might want to go to webopedia or something similar and read up on the MBR.

Regards,
BonezTheGoon

michaelb · Posted: Tue Aug 06, 2002 4:26 pm Post subject:

Grub won't be writing anything to a FAT32 partition. This is explanation is *way* oversimplified, but I think it will help clear up your confusion. When you boot up a computer, the first thing the BIOS does is look for information at the very beginning of the disk to find out where to go to load an OS into memory. When you install, say, Windows on a hard disk, it writes a little piece of very simple code on the first track of the disk telling the BIOS where it lives and how to load it. Very unfriendly to other OS's that happen to share that disk. What GRUB does, and LILO for that matter, is overwrite that code with a little pointer so some more code that gives the end user a choice of what OS to load. I have no problems with my dual boot system using GRUB to choose between Gentoo and Win2000 pro. If you do have a problem tho, and can't boot anything, it's very easy to fix. Get yourself a Win9x boot disk (they're everywhere, just google if you don't already have one) and boot from it. Then:

Greven60 · Guest

How would I use Lilo.... Grub hates me.

michaelb · Posted: Tue Aug 06, 2002 5:25 pm Post subject:

Well, what exactly are you doing to GRUB to make it hate you? I find GRUB to be an improvement over LILO, myself, but if you want to give something else a shot, your first order of business would be:

Greven60 · Guest

Well.... I follow the Help files to the letter but grub never starts up... and now I can't get back into my linux.

michaelb · Posted: Tue Aug 06, 2002 5:34 pm Post subject:

We're going to need some details here Greven. How many hard drives do you have? Are you running a dual boot, or does your Gentoo install have the entire disk(s)? What is your partitioning scheme? When you try to boot the computer, how far does it get? Any messages or anything?

Greven60 · Guest

Ok..... When It trys to boot it says,
"LI"

I have 3 HDD,
HDA = Windows and crap (Master IDE 1)
HDB = Games and more crap (Slave IDE 1)
HDC = Linux (Master IDE 2)
CD-Rom (Slave IDE 2)

When Try to get grub to place it's self in MBR it says that it's a fat and it stops. I would show you my grub but I can't get back in to gentoo.

michaelb · Posted: Tue Aug 06, 2002 9:05 pm Post subject:

FWIW, the "LI" is the behavior of a b0rked LILO, not GRUB. To get into your Linux system, boot from the install CD. Once there, just create your /mnt/gentoo and /mnt/gentoo/boot mount points and mount the appropriate partitions. You should now be able to check your menu.lst which should look something like: