> I have debian 5 on /dev/sda1 and ubuntu 10.04 on /dev/sda3
> here are my grub.cfg
> ### BEGIN /etc/grub.d/10_linux ###
> menuentry "Debian GNU/Linux, linux 2.6.26-2-amd64" {
> set root=(hd0,1)
> search --fs-uuid --set da13d632-e65a-4128-9b06-0ec24a5d390f
> linux /boot/vmlinuz-2.6.26-2-amd64
> root=UUID=da13d632-e65a-4128-9b06-0ec24a5d390f ro
> initrd /boot/initrd.img-2.6.26-2-amd64
> }
> ### END /etc/grub.d/10_linux ###
> ### BEGIN /etc/grub.d/30_os-prober ###
> ### END /etc/grub.d/30_os-prober ###
> ### BEGIN /etc/grub.d/40_custom ###
> menuentry "Ubuntu, with Linux 2.6.32-15-generic" {
> insmod ext2
> set root=(hd0,3)
> search --no-floppy --fs-uuid --set 76fe9a67-1168-4154-b994-4b466e92f7df
> linux /boot/vmlinuz-2.6.32-15-generic
> root=UUID=76fe9a67-1168-4154-b994-4b466e92f7df ro quiet splash
> initrd /boot/initrd.img-2.6.32-15-generic
> }
> ### END /etc/grub.d/40_custom ###
> whenever i choose to boot ubuntu, i got "unknown comand 'initrd' " but it is
> fine when i boot debian but not after i failed to boot ubuntu, debian would
> fail to boot too with the same message. How do i go about this?
1. Don't you have os-prober installed? Why is Ubuntu in the 40_custom section?
before going to number 2, is there any other way because os-prober did not detect ubuntu on /dev/sda3