Ubuntu
grub2 package

after trying to set a dual boot my ubuntu system doesn't boot properly

Asked by Dave Merritt

After screwing up the installation of kubuntu as a secondary OS on my ubuntu system, ubuntu won't boot properly. I thought i could install kubuntu onto an external drive, to keep the 2 OSs as independent as possible. But during installation it must have re-written the bios to boot only from that drive. Now in order to get into ubuntu I need to start from the bios boot menu. After unplugging and re-plugging the external i finally get to select my current version of ubuntu. Is it possible to restore the original boot settings? Also, if i leave the external out I get the "grub" prompt, which obviously mean grub can probably fix the problem. Unfortunately, I have no idea what to type in. Any ideas?

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Ubfan (ubfan1) said : 		#1

At the grub prompt without the external disk attached just to be sure, try (assuming your disk is sda):
device (hd0) /dev/sda
root (hd0)
setup (hd0)
quit

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delance (olivier-delance) said : 		#2

I suspect MBR of internal disk is pointing to /boot directory of external one.

Unplug external disk. Reinstall Grub2 from CD: https://help.ubuntu.com/community/Grub2#Reinstalling%20from%20LiveCD
Check you can reboot from internal disk to Ubuntu
Plug internal disk. Reinstall Grub2 from CD but be very careful about disk name. The order sda/sdb can't be predicted. Identify which disk is external one, and reinstall with both external partition (sda1 or sdb1) and external disk (sda or sdb).
Check you can reboot from internal disk to Kubuntu (and Ubuntu also if you want).
Unplug external disk. Check you can reboot from internal disk to Ubuntu

If it fails run following procedure:
----
Provide data about boot configuration

There is a standard script provided to analyse boot configuration.

Could you download script at:

   http://sourceforge.net/projects/bootinfoscript/

Then in a terminal (Ctrl+Alt+T) run command:

    sudo bash ./boot_info_script055.sh

This will produce a file named: RESULTS.txt

Paste content of this file in http://paste.ubuntu.com/ and provide in this thread the link to Web page.

Please don't post file directly in thread, else it will make thread difficult to read.

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Sam_ (and-sam) said : 		#3

Follow-up unfortunately is there.
https://answers.launchpad.net/ubuntu/+source/grub2/+question/147584

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