chainloading to grub

2handband · 12-21-2010, 08:38 AM

I'm setting up a dual-boot for a friend with Ubuntu Studio and Slackware 13.1. Slackware will be the primary OS and Lilo will control the bootloader. After doing some research it seemed to me the best way would be to chainload grub from the lilo menu, so when I installed Ubuntu I stuck Grub in the Ubuntu root partition instead of the MBR and added the following to Slackware's lilo.conf:

Code:

# Linux bootable partition config begins
image = /boot/vmlinuz-generic-2.6.33.4
  initrd = /boot/initrd.gz
  root = /dev/sda3
  label = Linux_Gen
  read-only  # Partitions should be mounted read-only for checking
  other = /dev/sdb2
  label = Ubuntu_Studio
# Linux bootable partition config ends

It's not working. It just errors out and asks me to boot something else when I select Ubuntu_Studio from the lilo menu. I've never tried this before so I'm sure I'm making a really basic and stupid error; could somebody tell me what I'm doing wrong?

witek · 12-21-2010, 08:55 AM

It should work. Are you sure Ubuntu is sdb not sda?
And maybe try for clarity to start the lilo entry for Ubuntu from new line and without spaces before it. Remember to reinstall lilo.

brianL · 12-21-2010, 09:11 AM

It might have something to do with Ubuntu Studio (any new Ubuntu) using GRUB2. That method used to work on previous releases of Ubuntu, and Debian "lenny".

2handband · 12-21-2010, 09:43 AM

Quote:

Originally Posted by witek

It should work. Are you sure Ubuntu is sdb not sda?
And maybe try for clarity to start the lilo entry for Ubuntu from new line and without spaces before it. Remember to reinstall lilo.

If I got 'em mixed up my Slackware wouldn't boot. It's correct. I'll try modifying the entry. I hope to God it's not a Grub2 issue. I have very little experience with dual-booting.

w1k0 · 12-21-2010, 10:30 AM

With Linux Mint I tried to install GRUB on the partition using ReiserFS but I failed. There is some bug in Mint's GRUB so it's also in Ubuntu's GRUB. The only way is to chainload from Ubuntu's GRUB to Slackware's LILO. For comparison Arch's GRUB works well -- it's possible to install it on the partition using ReiserFS.

If you'd like you could follow that thread: GRUB: Cannot find list of partitions && /usr/sbin/grub-setup: error.

2handband · 12-21-2010, 10:33 AM

So... if this is going to work, grub is going to have to take over the MBR.

Larry Webb · 12-21-2010, 11:52 AM

Try use ubuntu live and

grub-install --force /dev/sdb2

when finished reboot and see if that helped.

piratesmack · 12-21-2010, 12:02 PM

You should be able to do it this way.

Combine the Grub2 files 'lnxboot.img' and 'core.img'
e.g. if your Ubuntu partition is mounted on /mnt/ubuntu, you can do it with:

Code:

cat /mnt/ubuntu/boot/grub/{lnxboot.img,core.img} > /mnt/ubuntu/boot/grub2.img

This creates a file called 'grub2.img' that can be booted from LILO with a menu entry like:

Code:

image = /mnt/ubuntu/boot/grub2.img
  label = Grub2

Note: This method is kind of annoying because you'll always have to mount your Ubuntu partition before running /sbin/lilo. Personally, I prefer to just install Grub to the MBR when dual-booting.

2handband · 12-21-2010, 01:20 PM

Quote:

Originally Posted by piratesmack

You should be able to do it this way.

Combine the Grub2 files 'lnxboot.img' and 'core.img'
e.g. if your Ubuntu partition is mounted on /mnt/ubuntu, you can do it with:

Code:

cat /mnt/ubuntu/boot/grub/{lnxboot.img,core.img} > /mnt/ubuntu/boot/grub2.img

This creates a file called 'grub2.img' that can be booted from LILO with a menu entry like:

Code:

image = /mnt/ubuntu/boot/grub2.img
  label = Grub2

And it'll mount the Ubuntu root partition to /mnt/Ubuntu when lilo fires up?

piratesmack · 12-21-2010, 01:37 PM

Quote:

Originally Posted by 2handband

And it'll mount the Ubuntu root partition to /mnt/Ubuntu when lilo fires up?

No, lilo can't mount partitions because it doesn't understand filesystems.

When you run 'lilo', it will create a list of blocks occupied by the file 'grub2.img' and use that information to load it.

kapz · 12-21-2010, 01:42 PM

Quote:

it seemed to me the best way would be to chainload grub from the lilo menu, so when I installed Ubuntu I stuck Grub in the Ubuntu root partition instead of the MBR

If I were you, I would install grub2 on MBR and then again install lilo and chainload grub2 as primary partition.
For me it worked for FreeBSD bootloaderr and Minix bootloader, who knows it might as well work for you!

gnashley · 12-21-2010, 01:47 PM

Install grub-legacy manually and set it up to boot whatever and however you want.

2handband · 12-21-2010, 02:06 PM

Tried piratesmack's solution; still got "error 0x01" or something to that effect. Kapz, I'm not sure I undestand what you're suggesting, can you elaborate? Gnashley... I was hoping to leave lilo in control, but I may have to do what you're suggesting.

Larry Webb · 12-21-2010, 03:01 PM

Quote:

Originally Posted by gnashley

Install grub-legacy manually and set it up to boot whatever and however you want.

You can do that with grub2 also and it will read ext4 files.

w1k0 · 12-21-2010, 03:27 PM

2handband,

Thanks to gnashley I finally solved the problem concerning the installation of GRUB's bootloader at the beginning of the partition using ReiserFS. So I installed Slackware LILO's bootloader at MBR and now I can chainload Linux Mint's GRUB using Slackware's LILO.

To achieve that run the following commands in Ubuntu or Linux Mint:

sudo su -
apt-get remove grub-pc
apt-get install grub
update-grub # answer yes to the question about generating menu.lst
grub-install /dev/sda1

Then run Slackware, add to lilo.conf the following lines:

Quote:

other = /dev/sda1
label = mint

and run lilo command.