A little grub help.

miqorz · Posted: Fri Sep 24, 2004 11:36 pm Post subject: A little grub help.

Allright a couple days ago I install gentoo where Windows was.

And I've been booting gentoo with my OLD gentoo's grub.

Well I decided to install grub today and all I get is an error 18.

here's my entry.

miqorz · Posted: Sat Sep 25, 2004 2:53 am Post subject:

Hmm, I'm looking through some manual pages and it looks like everything I have listed is correct..

I get "Error 18" during "Grub Stage 1.5"

I'm using ext3 for /dev/hda1 without a boot partition.

TNorthover · Posted: Sat Sep 25, 2004 2:21 pm Post subject:

It''s been a while since I meddled with grub, but if you have a look in /boot/grub, and make sure e2fs_stage1_5 is there. There should also be your menu.lst or whatever you've called it, and a stage2 file.

If one of those is missing, you could try rerunning grub to install it. I think I put it on hda directly rather than any partitions. I just redid it and worked out the commands I used:

miqorz · Posted: Sat Sep 25, 2004 4:01 pm Post subject:

I did everything as stated above..

And I still get the Error 18.

Crap, I don't know what I'm doing wrong.

TNorthover · Posted: Sat Sep 25, 2004 4:31 pm Post subject:

OK, looking on the internet, it seems going into BIOS and fiddling around with the hard drive's LBA settings might work (someone mentioned setting it to large instead of LBA, another turning LBA on -- it'll be very hardware dependent). Possibly along with this would be changing the setup line in installing grub to "setup --force-lba (hd0)".

If that doesn't work, I suspect a separate boot partition at /dev/hda1 will, but it's always a pain to fiddle with partitions when things are installed (It should be possible without destroying your install though, provided your data doesn't take up more than half the drive -- using parted to resize and shuffle things about).

Those are the only two solutions I can think of. The problem is that it's trying to read past the 1024 cylinder BIOS may impose. So the only solutions are to stop BIOS imposing that limit (LBA settings, possibly including the force-lba to make grub use the BIOS properly), or make sure it doesn't run into that limit (make a separate boot partition with the kernel and grub on, and make sure all of that partition is below 1024 cylinders).

Having said that, there may be another way (wipe the partition and make sure grub's the first thing on there), but it'd be very unreliable and fragile to grub being upgraded (and possibly kernel upgrades too) -- almost certainly not worth pursuing.

amiatrome · Posted: Sat Sep 25, 2004 4:41 pm Post subject:

Found it in the Grub manual. Maybe it will shed some light.

miqorz · Posted: Sat Sep 25, 2004 8:18 pm Post subject:

Well I'm emerging parted and about to install gparted..

Let's hope for the best, eh?

TNorthover · Posted: Sat Sep 25, 2004 8:38 pm Post subject:

Oh dear, no luck then?

At the risk of teaching my grandmother to suck eggs, I'd suggest shrinking your current partition. Creating another one at the end. Copying everything across. Deleting old one. Creating boot and root. Copying everything back from backup. Deleting backup partition. Growing new root.

A bit like those towers of Hanoi really, but I can't think of a quicker way.

miqorz · Posted: Sat Sep 25, 2004 8:40 pm Post subject:

Heh, I'm just going to resize my root partition and create a /boot partition at the beginning.

TNorthover · Posted: Sat Sep 25, 2004 8:56 pm Post subject:

Eeek, apparantly you can't move the start block in resizing, so that's impossible. It mentions the restrictions at the homepage

miqorz · Posted: Sat Sep 25, 2004 9:02 pm Post subject:

crap, I may just reinstall :\

TNorthover · Posted: Sat Sep 25, 2004 10:15 pm Post subject:

You could try LILO or something on the off-chance if you don't want to spend hours recompiling.

miqorz · Posted: Sat Sep 25, 2004 11:43 pm Post subject:

I hate lilo (personal prefrence.)

I'm in Knoppix right now downloading a stage3 tarball.

It's a good thing I put home on it's own partition or I'd be really pissed right about now.