2

I just upgraded from Oneiric to Precise and it messed up my GRUB2, now I can't boot and keep getting an "error: no such partition" error. This is not the first time this happens but now I can't seem to boot from usb (separate question) to repair GRUB2 and I can't find my way in the Rescue Console.

Community
  • 1
t3mujin
  • 375
  • 3
  • 13

2 Answers2

1

You can use few ways to restore your grub. Most simple way is loading your Ubuntu Live CD with
no acpi no apic no lapic no raid no modeset options
( F6 on boot screen and select all for exclusion Free Software Only ),
choose Try Ubuntu, and:

  • Tune Network connection and connect Internet.
  • Run terminal.

  • Run: 

    sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

In your Guest session will be installed Boot Repair program.

How to use it and more information about restoring boot you can read here:
Ubuntu Documentation > Community Documentation > Boot-Repair

More complicated way:
Grub Rescue commands

swift
  • 3,261
  • 2
  • 22
  • 46
  • Why boot with the `no acpi` `no apic` `no lapic` `no raid` `no modeset` options? Why not just boot the **Ubunut Live CD** and run `boot-repair`? – irrational John Apr 17 '12 at 01:49
  • despite the fact that no necessary options, disabling ACPI and EDD (Enhanced Disk Drive) can avoid occurs some errors with mounting guest session + installing boot-repair ... so disabling signed set will create maximally virtual session and avoiding unneeded dependencies. though, sure, it's only my own experience. – swift Apr 17 '12 at 02:20
  • 1
    `acpi=off` must be used with caution. Use it as last resort, it can cause to overheat and permanent damage to system. More info -> http://ubuntuforums.org/showthread.php?t=1613132 – Web-E Apr 17 '12 at 02:31
  • it's actual for running of **full installed system**. _Guest session_ is limited for resource consumption and it's appropriate for rapid Live Ubuntu repair session. – swift Apr 17 '12 at 02:43
  • settings on boot screen of Live CD not related to Grub installed on HDD partition ... It's options for booting from CD. – swift Apr 17 '12 at 02:48
1

I think the simplest way to restore grub (what should fix your problem) is to burn a Super Grub2 Disk, then boot from it, choose to scan for operationg systems, start Ubuntu, log in and execute the command sudo update-grub.

EDIT: If that doesn't work, do the same again but this time execute sudo grub-install /dev/sdX. sdX has to be replaced with the real harddrives dev-name. Do not do this unless you are sure you are doing it for the right harddrive!

jplatte
  • 1,290
  • 9
  • 20