After a few days of inactivity, you have turned your computer back on but finding that it is no longer able to start correctly. Within this new guide today, therefore, we will find out together how to repair PC Linux that does not start using one of the 3 proposed solutions.
Even if the computer does not boot properly, it can be restored without necessarily upgrading the operating system. Therefore, we advise you not to reinstall the Linux distribution but first follow the instructions we will give you in the next bars. Before discovering the steps, however, you need a working PC to be able to download the ISO images and burn them to a USB device.
How to repair a Linux PC that does not boot with Super Grub Disk
The simplest solution to start a Linux PC with a damaged bootloader is to use Super Grub Disk. It is a live disk that can detect all the operating systems installed on any computer and start them.
The first thing to do is to download the Super Grub Disk ISO and burn it on an empty CD / DVD or on a USB key, making it bootable. For this tutorial, we recommend using Etcher as it is available for all major OS such as Windows (portable version), macOS and Linux (via AppImage). The operation of this software is practically identical on all 3 operating systems.
To download the Super Grub Disk ISO image, open the default browser and connect to the download page and click on the Super Grub2 Disk link (CD & USB in one) x.xx (ISO). You will be redirected to the Source Forge site. To proceed with the download, simply wait for the countdown to end.
Now, you have to get Etcher. To do this, connect to the Internet site of the Whale and click Download for Windows (x86 | x64), Download for MacOS, Download for Linux x64 (64-bit) (App-Image) or Downloads for Linux x86 (64-bit) (App-Image) depending on the operating system installed on your computer. Don’t worry because the site will automatically detect the installed OS.
Once downloaded, start Etcher, click the button Select image and select the ‘ ISO of Super Grub Disk. Once this is done, press Select drive and select the CD / DVD drive with the blank disk or USB stick. Complete the operation by simply pressing on Flash! At the end of the burning process, the powerful tool can finally be used.
To do this, connect the bootable USB stick to one of the computer’s USB ports or insert the CD / DVD into the appropriate drive and set it as the first BIOS boot device. For more information, check out the tutorials below.
Through the screen that appears, choose Detect and show boot methods and date Enter. Super Grub Disk at this point shows you all the operating systems on the computer that can be loaded. Use the arrow keys to select the OS that you can’t get started when you first turn on your computer and enter.
With the help of Super Grub Disk, you were able to get your Linux operating system started even though the GRUB is damaged. But now it’s time to reinstall the bootloader so that everything can return to normal.
If you want the BIOS / MBR layout, open the terminal and type the command sudo grub-install –recheck –target = i386-pc / dev /sda.
Once this is done, a new configuration file must be created. This is a necessary operation otherwise the bootloader may not detect the changes made. Give the command sudo grub-mkconfig -o /boot/grub/grub.cfg .
Alternatively, if you want the GPT / EFI layout, then use the following commands:
grub-install –target = x86_64-efi –efi-directory = / boot –bootloader-id = grub
sudo grub-mkconfig -o /boot/grub/grub.cfg
How to repair a Linux PC that does not boot up via backup
Even if the GRUB behaves most of the time well, it is always better to have a backup in order to use it in case of problems. For most users, Super Grub Disk is a good option but there is an alternative. Since Linux is an extremely versatile operating system, however, it is possible to install the GRUB bootloader directly on a USB stick. This way, if the distro refuses to boot, you can connect it to one of the available USB ports and proceed without problems.
Before discovering the steps to follow, it is important that the USB stick is formatted in FAT32 (or FAT ).
At this point, create a folder called USB in / mnt through the command mkdir -p/mnt/usb and then use lsblk to identify the tag of the pendrive (eg sdc1 ).
Once this is done, mount the USB key inside the USB folder created previously using mount/dev/ sdc1 / mnt/usb. Obviously, replace sdc1 with the label of the USB storage device.
In the next step, proceed with the installation of GRUB on the USB flash drive through the command grub-install –target = i386-pc –debug –boot-directory = / mnt / usb/boot / dev / sdc . In conclusion, create a configuration file for the pendrive with grub-mkconfig -o /mnt/usb/boot/grub/grub.cfg .
How to repair a Linux PC that does not boot with Rescatux
Neither of the two options listed above worked? As an alternative, we propose Rescatux. Just like Super Grub Disk, we are faced with a real live rescue disk that allows you to restore the GRUB bootloader. Let’s talk about a perfect tool for those who failed to reinstall it via the command line.
Before seeing the steps to follow, however, we wanted to clarify that this is software available at this time only in beta, so it may not always work properly.
That said, open the default browser, connect to the download page of Rescatux Beta and click the link Rescatux xx ISO (672 MB) to download the ISO. Alternatively, press on (Torrent) to proceed with downloading via torrent. You will be directed to the Source Forge website where to proceed with the download once the countdown is complete.
Download the ISO, use Etcher to burn it on a USB stick or on a blank disk following the same steps seen for Super Grub Disk. Once the installation is complete, we advise you to follow the directions of the GNU GRUB manual as it is a complicated and very difficult process.