Resetting a root password in Linux without external media

We have to follow 8 steps to crack root password without using any external media

• Step-1 : Reboot the system and interrupt the boot loader countdown timer by pressing any key except enter.
• Step-2 :  Find the entry that is normally booted, and change it to halt execution during the initial ram disk.
  • 2.1. Use the cursor keys to highlight the entry that is normally booted and press e
  • 2.2. Use the cursor to move to the line that has the kernel and kernel arguments. This line normally starts with

    linux16 or linuxefi.

  • 2.3. Move the cursor to the end of line by pressing End, and add rd.break.
  • 2.4. Press Ctrl+x to boot using the modified stanza and you will get a command line interface.
    

    

• Step-3: On command line Interface you have to write command

  # mount -o remount,rw /sysroot

  Here we are mounting the system read-write . The file system is mounted under /sysroot.

• Step-4 : Change the working root to /sysroot directory.

  # chroot /sysroot

• Step-5 : Now you can change password

  #passwd root

• Step-6 : Now make sure that all the unlabeled files(like /etc/shadow) get relabeled during boot so run the command

  #touch /.autorelabel

  

• Step-7 : Now by running command exit you can exit from interactive shell.

  # exit

• Step-8 : Now again run exit command by which you can exit from command line interface and booting process will start again with new root password.

  # exit