Slackware boot error after fresh install

Question

I'm currently running Ubuntu and Slackware on my system. After just installing Slackware, with everything appearing to work fine, I boot into GRUB only to see an "error: no such disk" or something of another when I try to load Slackware. Does anyone know why this is the case?

update

I first installed Slackware with a full install on one of my partitions, a swap included. During this time I chose not to install LILO. After this, I then proceeded to install Ubuntu just so I could have something which would work when I needed it to. This is when I installed GRUB2, and when Slackware just refused to work.

Should I reinstall it with LILO this time? If I do this, will it scrap my Ubuntu or should I still be able to use it?

update 2

I think this is the problem:

menuentry "Slackware Linux (Slackware 13.37.0) (on /dev/sda8)" --class gnu-linux --class g      nu --class os {
       insmod part_gpt
       insmod ext2
       set root='(/dev/sda,gpt8)'
       search --no-floppy --fs-uuid --set=root 89ba52ea-8afa-4d93-adac-e4a9258a2aae
       linux /boot/vmlinuz root=/dev/sda8
  }

I don't know much about grub.cfg, but from it seems like (and from what I've been reading of the ubuntu documentation), this appears to be correct. I think the uuid isn't being found, however. Should I replace the uuid with the partition it's located on?

Answer 1

If Slackware is on sda8, then your /etc/grub.d/40_custom file should look like:

#!/bin/sh
exec tail -n +3 $0

menuentry "Slackware" {
set root=(hd0,8)
linux /boot/vmlinuz root=/dev/sda8 ro quiet
}

You can use UUIDs, which would then look something like:

#!/bin/sh
exec tail -n +3 $0

menuentry "Slackware"{
set root=(hd0,8)
search --no-floppy --fs-uuid --set cf984a2a-8892-4d79-a0dc-2fc81ee04edb
linux /boot/vmlinuz root=/dev/disk/by-uuid/cf984a2a-8892-4d79-a0dc-2fc81ee04edb ro vga=872
}

Make sure that you run update-grub as root to apply the changes...