{"id":12669,"date":"2019-03-28T06:54:14","date_gmt":"2019-03-28T06:54:14","guid":{"rendered":"http:\/\/www.appservgrid.com\/paw92\/?p=12669"},"modified":"2019-03-28T06:54:14","modified_gmt":"2019-03-28T06:54:14","slug":"how-to-rescue-repair-and-reinstall-grub-boot-loader-in-ubuntu","status":"publish","type":"post","link":"https:\/\/www.appservgrid.com\/paw92\/index.php\/2019\/03\/28\/how-to-rescue-repair-and-reinstall-grub-boot-loader-in-ubuntu\/","title":{"rendered":"How to Rescue, Repair and Reinstall GRUB Boot Loader in Ubuntu"},"content":{"rendered":"

This tutorial will guide you on how to rescue, repair or reinstall a damaged Ubuntu machine which cannot be booted due to the fact that the Grub2 boot loader has been compromised and cannot load the boot loader which transfers the control further to the Linux kernel. In all modern Linux operating systems GRUB is the default boot loader.<\/p>\n

This procedure has been successfully tested on an\u00a0Ubuntu 16.04<\/strong>\u00a0server edition with the Grub boot loader damaged. However, this tutorial will only cover Ubuntu server GRUB rescue procedure, although the same procedure can be successfully applied on any Ubuntu system or on the majority of Debian-based distributions.<\/p>\n

Requirements<\/h4>\n
    \n
  1. \n
      \n
    1. Download Ubuntu Server Edition DVS ISO Image<\/a><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n

      You try to boot your Ubuntu server machine and you see that the operating systems no longer starts-up and you discover that the boot loader program no longer works?<\/p>\n

      Typically, the\u00a0GNU GRUB<\/strong>\u00a0minimal console appears on your screen, as illustrated on the below screenshot. How can you restore the Grub in Ubuntu?<\/p>\n

      \n

      \"Ubuntu<\/p>\n

      Ubuntu Grub Console<\/p>\n

      There are a lot of methods in Linux that can be used to re-install a broken grub, some can involve the ability to work and restore the boot loader by using the Linux command line and others are fairly simple and implies booting the hardware with a Linux live CD and using the GUI indications to repair the damaged boot loader.<\/p>\n

      Among the simplest methods, that can be used in Debian based distributions, especially on Ubuntu systems, is the method presented in this tutorial, which involves only booting the machine into the Ubuntu live DVD ISO image.<\/p>\n

      The ISO image can be downloaded from the following link:\u00a0http:\/\/releases.ubuntu.com\/<\/a><\/p>\n

      Reinstall Ubuntu GRUB Boot Loader<\/h3>\n

      1.<\/strong>\u00a0After you\u2019ve downloaded and burned the\u00a0Ubuntu ISO<\/strong>\u00a0image, or created a bootable USB stick, place the bootable media into your appropriate machine drive, reboot the machine and instruct the\u00a0BIOS<\/strong>\u00a0to boot into Ubuntu live image.<\/p>\n

      \n

      \"Machine<\/p>\n

      Machine Boot Menu<\/p>\n<\/div>\n

      2.<\/strong>\u00a0On the first screen, choose the\u00a0language<\/strong>\u00a0and press\u00a0[Enter]<\/strong>\u00a0key to continue.<\/p>\n

      \n

      \"Choose<\/p>\n

      Choose Language<\/p>\n<\/div>\n

      3.<\/strong>\u00a0On the next screen, press\u00a0F6<\/code>\u00a0function key in order to open the other options menu and select\u00a0Expert<\/strong>\u00a0mode option. Then, hit\u00a0Escape<\/strong>\u00a0key to return to\u00a0Boot Options<\/strong>\u00a0line in editing mode, as illustrated in the below screenshots.<\/p>\n

      \n

      \"Ubuntu<\/p>\n

      Ubuntu Expert Mode<\/p>\n<\/div>\n

      \n

      \"Ubuntu<\/p>\n

      Ubuntu Boot Options<\/p>\n<\/div>\n

      4.<\/strong>\u00a0Next, edit Ubuntu live image boot options by using the keyboard arrows to move the cursor just before the\u00a0quiet<\/code>\u00a0string and write the following sequence as illustrated in the below screenshot.<\/p>\n

      rescue\/enable=true \r\n<\/pre>\n
      \n
      \"Enable<\/p>\n
      Enable Ubuntu Rescue Boot Option<\/p>\n<\/div>\n
      5.<\/strong>\u00a0After you\u2019ve wrote the above statement, press\u00a0[Enter]<\/strong>\u00a0key to instruct the live ISO image to boot into rescue mode in order to Rescue a broken system.<\/p>\n
      \n
      \"Ubuntu<\/p>\n
      Ubuntu Rescue Mode<\/p>\n<\/div>\n
      6.<\/strong>\u00a0On the next screen select the language you want to perform the system rescue and press\u00a0[enter]<\/strong>\u00a0key to continue.<\/p>\n
      \n
      \"Choose<\/p>\n
      Choose Language in Rescue Mode<\/p>\n<\/div>\n
      7.<\/strong>\u00a0Next, select your appropriate location from the presented list and press\u00a0[enter]<\/strong>\u00a0key to move further.<\/p>\n
      \n
      \"Select<\/p>\n
      Select Your Location<\/p>\n<\/div>\n
      8.<\/strong>\u00a0On the next series of screens, select your\u00a0keyboard layout<\/strong>\u00a0as illustrated in the below screenshots<\/p>\n
      \n
      \"Configure<\/p>\n
      Configure Keyboard<\/p>\n<\/div>\n
      \n
      \"Select<\/p>\n
      Select Keyboard Country Layout<\/p>\n<\/div>\n
      \n
      \"Select<\/p>\n
      Select Keyboard Layout<\/p>\n<\/div>\n
      9.<\/strong>\u00a0After detecting your machine hardware, loading some additional components and configuring the network you will be asked to setup your machine\u00a0hostname<\/strong>. Because you\u2019re not installing the system, just leave the system hostname as default and press\u00a0[enter]<\/strong>\u00a0to continue.<\/p>\n
      \n
      \"Detecting<\/p>\n
      Detecting System Hardware<\/p>\n<\/div>\n
      \n
      \"Keep<\/p>\n
      Keep System Hostname<\/p>\n<\/div>\n
      10.<\/strong>\u00a0Next, based on the supplied physical location the installer image will detect your\u00a0time zone<\/strong>. This setup will accurately work only if your machine is connected to internet.<\/p>\n
      However, it\u2019s unimportant if your time zone is not correctly detected, because you are not performing a system installation. Just press\u00a0Yes<\/code>\u00a0to continue further.<\/p>\n
      \n
      \"Keep<\/p>\n
      Keep Timezone<\/p>\n<\/div>\n
      11.<\/strong>\u00a0On the next screen you\u2019ll be directly transferred into rescue mode. Here, you should choose your machine root file system from the provided list. In case your installed system uses a logical volume manager to delimit partitions, it should be easy to detect your\u00a0root<\/strong>\u00a0partition from the list by reviewing volume group names as illustrated in the below screenshot.<\/p>\n
      Otherwise, in case you\u2019re not sure which partition is used for the\u00a0\/(root)<\/code>\u00a0file system, you should try to probe each partition until you detect the root file system. After selecting the root partition press\u00a0[Enter]<\/strong>\u00a0key to continue.<\/p>\n
      \n
      \"Choose<\/p>\n
      Choose Root Partition<\/p>\n<\/div>\n
      12.<\/strong>\u00a0In case your system has been installed with a separate\u00a0\/boot<\/code>\u00a0partition, the installer will ask you whether you want to mount the separate\u00a0\/boot<\/strong>\u00a0partition. Select\u00a0Yes<\/code>\u00a0and press\u00a0[Enter]<\/strong>\u00a0key to continue.<\/p>\n
      \n
      \"Mount<\/p>\n
      Mount Boot Partition<\/p>\n<\/div>\n
      13.<\/strong>\u00a0Next, you will be provided with\u00a0Rescue operations<\/strong>\u00a0menu. Here, select the option to\u00a0Reinstall the GRUB boot loader<\/strong>\u00a0and press\u00a0[enter]<\/strong>\u00a0key to continue.<\/p>\n
      \n
      \"Reinstall<\/p>\n
      Reinstall Ubuntu Grub Loader<\/p>\n<\/div>\n
      14.<\/strong>\u00a0On the next screen, type your machine disk device where the GRUB will be installed and press\u00a0[Enter]<\/strong>\u00a0to continue, as shown in the below image.<\/p>\n
      Usually, you should install the boot loader on your first machine hard disk MBR, which is \/dev\/sda<\/code>\u00a0in most cases. The installation process of GRUB will start as soon as you hit the\u00a0Enter<\/strong>\u00a0key.<\/p>\n
      \n
      \"Select<\/p>\n
      Select Disk to Install Grub Loader<\/p>\n<\/div>\n
      15.<\/strong>\u00a0After the live system installs the\u00a0GRUB boot loader<\/strong>\u00a0you will be directed back to main\u00a0rescue mode<\/strong>\u00a0menu. The only thing left now, after you\u2019ve successfully repaired your\u00a0GRUB<\/strong>, is to\u00a0reboot<\/strong>\u00a0the machine as shown in the below images.<\/p>\n
      \n
      \"Installing<\/p>\n
      Installing Ubuntu Grub Boot Loader<\/p>\n<\/div>\n
      \n
      \"Reboot<\/p>\n
      Reboot Ubuntu System<\/p>\n<\/div>\n
      Finally, eject the live bootable media from the appropriate drive, reboot the machine and you should be able to boot into the installed operating system. The first screen to appear should be installed operating system GRUB menu, as illustrated in the below screenshot.<\/p>\n
      \n
      \"Ubuntu<\/p>\n
      Ubuntu Boot Menu<\/p>\n<\/div>\n
      Manually Reinstall Ubuntu Grub Boot Loader<\/h3>\n
      14.<\/strong>\u00a0However, if you like to manually reinstall the GRUB boot loader from\u00a0Rescue operations<\/strong>\u00a0menu, follow all the steps presented in this tutorial until you reach point 13, where you make the following changes: instead of choosing the option to reinstall GRUB boot loader, select the option which says\u00a0Execute a shell in \/dev\/(your_chosen_root_partition<\/strong>\u00a0and press\u00a0[Enter]<\/strong>\u00a0key to continue.<\/p>\n
      \n
      \"Select<\/p>\n
      Select Execute a Shell in Root Partition<\/p>\n<\/div>\n
      15.<\/strong>\u00a0On the next screen hit\u00a0Continue<\/strong>\u00a0by pressing\u00a0[enter]<\/strong>\u00a0key in order to open a shell in your root file system partition.<\/p>\n
      \n
      \"Open<\/p>\n
      Open Shell Mode<\/p>\n<\/div>\n
      16.<\/strong>\u00a0After the shell has been opened in the root file system, execute\u00a0ls command<\/a>\u00a0as presented below in order to identify your machine hard disk devices.<\/p>\n
      # ls \/dev\/sd* \r\n<\/pre>\n
      After you\u2019ve identified the correct hard disk device (usually the first disk should be\u00a0\/dev\/sda<\/code>), issue the following command to install the GRUB boot loader on the identified hard disk MBR.<\/p>\n
      # grub-install \/dev\/sda\r\n<\/pre>\n
      After GRUB has been successfully installed leave the shell prompt by typing exit.<\/p>\n
      # exit\r\n<\/pre>\n
      \n
      \"Install<\/p>\n
      Install Ubuntu Grub Boot Loader<\/p>\n<\/div>\n
      17.<\/strong>\u00a0After you\u2019ve exited the shell prompt, you will be returned to main\u00a0rescue mode<\/strong>\u00a0menu. Here, choose the option to\u00a0reboot<\/strong>\u00a0the system, eject the live bootable ISO image and your installed operating system should be booted without any issue.<\/p>\n
      \n
      \"Reboot<\/p>\n
      Reboot System<\/p>\n<\/div>\n
      That\u2019s all! With a minimal effort you\u2019ve successfully rendered your Ubuntu machine the ability to boot the installed operating system.<\/p>\n
      Source<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
      This tutorial will guide you on how to rescue, repair or reinstall a damaged Ubuntu machine which cannot be booted due to the fact that the Grub2 boot loader has been compromised and cannot load the boot loader which transfers the control further to the Linux kernel. In all modern Linux operating systems GRUB is … <\/p>\n
      Continue reading “How to Rescue, Repair and Reinstall GRUB Boot Loader in Ubuntu”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-12669","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/12669","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/comments?post=12669"}],"version-history":[{"count":1,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/12669\/revisions"}],"predecessor-version":[{"id":12670,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/12669\/revisions\/12670"}],"wp:attachment":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/media?parent=12669"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/categories?post=12669"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/tags?post=12669"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}