RHEL Recover root Password

RHEL7

1. Reboot OS into emergency mode.
2. During the GRUB2 countdown, Edit the first line by pressing "e".
   1. Locate the line that reads "linux16".
      1. Immediately following the "quiet" keyword append "rd.break"
3. Continue the boot process.
   1. Press Ctrl-x to boot.
4. The system will boot into emergency mode and the switch_root prompt will appear.
5. Remount the /sysroot filesystem as rw.
   1. # mount -o remount,rw /sysroot
6. chroot to the /sysroot filesystem.
   1. # chroot /sysroot
7. Create a new password.
   1. # passwd
8. Update the SELinux Security Context.
   1. touch /.autorelabel
9. Exit the /sysroot chroot.
   1. # exit
10. Exit emergency mode.
    1. # exit

RHEL8/RHEL9

1. Reboot OS into emergency mode.
2. During the GRUB2 countdown, Edit the first line by pressing "e".
   1. Locate the line that reads "linux".
      1. Immediately following the "quiet" keyword append "rd.break"
3. Continue the boot process.
   1. Press Ctrl-x to boot.
4. The system will boot into emergency mode and the switch_root prompt will appear.
5. Remount the /sysroot filesystem as rw.
   1. # mount -o remount,rw /sysroot
6. chroot to the /sysroot filesystem.
   1. # chroot /sysroot
7. Create a new password.
   1. # passwd
8. Update the SELinux Security Context.
   1. touch /.autorelabel
9. Exit the /sysroot chroot.
   1. # exit
10. Exit emergency mode.
    1. # exit

Further Reading

1. RHEL7 Changing and resetting the root password
2. RHEL8 Changing and resetting the root password
3. RHEL9 Changing and resetting the root password