Debian grub repair tool

Note : The Boot Repair tool is available as a live image , so you can boot it from an external drive without using another live OS. Mount the partition containing the OS installation. For another way to fix your boot-related issues, read How to Use fsck Command. Introduction The GRUB Grand Unified Bootloader is a tool for booting and loading operating system kernels and the default bootloader for systems based on the Linux kernel.

Was this article helpful? Marko Aleksic. His innate curiosity regarding all things IT, combined with over a decade long background in writing, teaching and working in IT-related fields, led him to technical writing, where he has an opportunity to employ his skills and make technology less daunting to everyone. Next you should read. Security SysAdmin. In this step-by-step guide, you will learn how to build and compile a Linux kernel from scratch, for disabling drivers or trying experimental patches.

Backup and Recovery SysAdmin. The fsck File System Consistency Check Linux utility checks filesystems for errors or outstanding issues. Normally, the OS is booted from the first partition of the hard disk. In this case, to verify that the bootable partition is 'msdos1', let's run the following command:. If you are unable to boot your system which might be due to bad filesystem, or due to missing GRUB configuration file , you will need to boot from some other medium. Once you have booted into your system, you might need to create the GRUB configuration files, if missing or if misconfigured.

To create these configuration files, run:. This command needs superuser privileges. So run this command and the following commands in this article as root. This will fix the problem caused by Windows, in which Windows installs its bootloader on MBR, after installation of Windows over Linux.

Here I assume that you have booted from the Live or rescue CD. You can choose your own mount point, and your root filesystem partition may be different. If you wish to install it on some partition, replace the last argument of the above command with the proper partition. I'm going to highly recommend you use the desktop version of Ubuntu--there's a very handy graphical tool that can fix the problem.

Either way, make sure you've created your bootable USB device before you attempt this. Although we'll be using a Ubuntu Desktop live instance, the process will work, even if you're repairing, say, Fedora or CentOS.

Once the desktop appears, make sure there's a working network connection and open the terminal window. What we're going to do now is install a tool called boot-repair.

To do that, add the necessary repository with the command:. The tool will run through the standard fixes for GRUB2. When the process completes, boot-repair will ask you if you want to upload the report to a pastebin Figure B. When the upload completes, boot-repair will present to you a URL that you can use to view the report Figure C. If you want to see what boot-repair did to your system, copy and paste the URL into a browser and give the report a read.

Remember, that the Pastebin post will expire in a couple of days, so make sure you give it a read soon, otherwise you'll miss out on seeing what the tool did to fix GRUB2. In my case, what boot-repair did was re-install the GRUB2 boot loader with the commands:. If boot-repair fails to fix GRUB2, you might have to run through the same process, but click the Advanced Options button to access some of the extra features Figure D.

Note: You should not use the Advanced Options unless you know what you're doing. Once boot-repair has completed the process, reboot your machine, remove the USB drive, and cross your fingers that the boot loader has been successfully repaired.