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Recover the Root Password in RHEL 7


Booting into Rescue Mode

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Resetting root password on MySQL Minimalistic and Rescue Linux Distributions

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If you boot a RHEL 7 system into the rescue or emergency target, you are prompted for the root password. But what if you have forgotten the password? This exercise shows the steps required to reset a lost password for the root user. During the password-recovery process, you probably won’t have access to documentation. Hence, you should practice the following procedure until you can use it in a crisis:

  1. Reboot the server.
  2. When you see the following message, press a key to access the GRUB menu:
  3.  Press E to edit the current menu entry.
  4. Scroll down with the DOWN ARROW key to locate the line starting with linux16. Press CTRL-E or END to move to the end of the line, and then type the string rd.break.
  5. Press CTRL-X to boot the system.
  6. The rd.break directive interrupts the boot sequence before the root filesystem is properly mounted. Confirm this by running ls /sysroot. If you know the contents of the root filesystem, the output should look familiar.
  7. Remount the root /sysroot filesystem as read-write and change the root directory to /sysroot:

10.  Change the root password:

11.  Because SELinux is not running, the passwd command does not preserve the context of the /etc/passwd file. To ensure that the /etc/passwd file is labeled with the correct SELinux context, instruct Linux to relabel all files at the next boot with the following command:

touch /.autorelabel 

12.  Type exit to close the chroot jail, and then type exit again to reboot the system.

13.  It may take a few minutes for SELinux to relabel all files. Once you get a login prompt, confirm that you are able to log in as the root user.