System recovery on Ubuntu Problem 1: You have started to install and use Ubuntu. After a while, for example, when installing critical updates, you may encounter a problem of not reaching the Ubuntu desktop after a power failure - you may encounter a black screen, or you may get a desktop with a poor resolution, you may experience problems such as not working with hardware such as network card, sound card, Issue 2: After making a similar change to your video card drivers, you may not be able to reach your desktop, or you may encounter a problematic desktop with a resolution. Issue 3 If you have Windows and Ubuntu installed on your computer, you will need to repair the boot system to reach Ubuntu after each reinstallation of Windows. In such cases, you need to know how to recover your system and how to access the data on your computer. This document will tell you how to recover the system if you encounter the above problems and how to get your documentation even if you save the system. Ubuntu's use of Rescue Mode options If you are unable to reach the desktop after a critical update error as described in Problem 1 and Problem 2, or if you encounter various hardware problems after the user has changed the video card settings, the operating system selection screen shown in Figure 1 options ". If you continue with this option, a screen will appear as shown in Figure 2. Figure 1: Continue with the "Advanced options for Ubuntu" option in the opening menu. Figure 2: Recovery kiosks with old and new Linux kernels Figure 2 shows a list of many Ubuntu options and options of these options (Rescue Mode). We can explain these options as follows: From time to time, with some updates you made on Ubuntu, the Linux kernel, the basic building block of the operating system, is being updated. After core updates, rafa is removed instead of removing old cores altogether. Here are the options in this list, the old Linux kernel that has been raised rafa, and the recovery of these versions. To solve the problem you are experiencing, or to skip over a properly working desktop, you can try opening the system using one of the older cores, as described below. If it does not work, you can use the Recovery Mode options as described in the next section. Use of old cores: You can see if the problem persists using any of the old Linux kernels in this list (which does not mention the "recovery mode"), after the update mentioned above. Starting with the top core, you will have to look at the result because the topmost option is more current than the others. Using the Recovery Mode options: For each core option that is shown in Figure 2, there is also an option in the paratez that says "rescue mode". If you want to solve the problem you are experiencing with the rescue mode options, you can start by trying the top of the options with "rescue mode" next to it. When you continue using the recovery mode option in the list, you will see a screen that presents the following options. Figure 3: Recovery options Now let's explain under what conditions the recovery options shown in the illustration can work. clean: try free space If you go to the username-password entry screen when you turn on the computer, but you enter your username and password correctly on this screen and you go back to the user login screen without opening the desktop, this may be because the disk partition on which Ubuntu is installed is completely full. dpkg: Repair bad packages When installing updates on Ubuntu or installing any package, power failure etc. due to the sudden shutdown of the computer or incompatible packages you subsequently installed into Ubuntu, the packet data base may be corrupted. In such cases, you can use this option to repair the packet database. However, this may not be sufficient to solve a problem that may arise from the fact that an important update is in the process. If it is not enough, first enable the network connection using the "network" option below and then use the "root" option to load all remaining updates via the command line as described below (in the root section). After installing the updates, use the "dpkg" option again (or use the command sudo dpkg-reconfigure --all to restore the package database while in the command line) failsafeX: If a change is made to the display card driver, you may encounter problems such as not reaching your desktop or encountering a broken screen. If you are having problems with your video card configuration, you can try the "failsafeX" option to get to your desktop or try turning to the predefined open source driver as described in the Open source driver feedback page on the Closed source driver page. The failsafeX option attempts to turn on the system using drivers that have very low features for your display card, but can safely run them. fsck: Mark all file systems grub: Update Grub boot loader This option rescans all disks inserted in the computer and detects the installed operating systems and updates the Grub menu. If another Linux distribution is installed in addition to a hard disk on a Ubuntu computer and its own boot loader can not be installed when this Linux distribution is installed, this option will allow the newly installed operating system to be added to the GRUB menu on the computer startup. Also this option; can also be used when an operating system with a portable diskette is installed in the GRUB menu. In fact, all these GURB menu updates can be done while on Ubuntu desktop. It is enough to use sudo update-grub command in Terminal. This option; There is no interest in resolving situations where the Grub menu is damaged due to any reason or that the Grub menu never arrives. If you are experiencing this kind of problem, you can repair the Grub by performing the steps described in the repairing (reinstalling) Grub boot loader. network: Enable network connection A few seconds after you use this option, your network connection will be established automatically. You can use the Ctrl + Alt + PrtScr (SysRq) key combination to return to the previous screen (that is, the screen with the recovery mode options) after your network connection is established. root: Enter the authorized user on the command line Even if your desktop is not open, you can easily do any kind of repair and update using the command line screen. If you can not reach the desktop due to power failure while installing important updates, first activate your network connection using the network option. Then switch to the command line screen using the "root" option. By default, the recovery mode binds the file system as read-only. To connect as writable, issue the following command: mount -o rw, remount / To update the whole system at the command line, first issue the sudo apt-get update command followed by sudo apt-get upgrade. After you are done, you can restart the computer using the reboot command. Repairing the startup system after Windows installation Selecting the operating system at computer startup If you have installed Windows and Ubuntu on your computer; Every time you reinstall Windows without touching Ubuntu, the operating system selection screen called "GRUB" at the computer startup will disappear from the center and Windows will be opened directly. In such cases, you will need to repair the GRUB boot boot software to restore the operating system selection screen. Repairing the boot system may be needed not only for Windows installation, but also for failure of the Grub menu due to any reason. You can get detailed information on how to repair the boot boot system by repairing (reinstalling) the Grub boot loader. With Ubuntu live DVD / USB, you can access the documents on your computer Ubuntu "Trial" or "Setup" selection screen If you have a Ubuntu or any other operating system (Windows, etc.) installed on your computer that crashes, you may want to copy your files and copy them to a secure external diskette. In such cases you can take advantage of Ubuntu's live DVD / USB feature. To do this, insert any Ubuntu version DVD or USB stick on the computer and launch it from this DVD or USB memory. Use the "Try Ubuntu Version" option when the screen on the side comes up. You are now in Ubuntu live DVD / USB's desktop environment. Open the file manager by clicking on the folder icon in the launcher bar on the left side of the desktop. This file manager window allows you to access the partition of your documents. You can copy the data you have to an external diskette in your hand. In fact, before you come to face this kind of accident, You will always use it as a disk, not just on disk partitions where Ubuntu or other operating systems are installed, but on a disk partition.