how to reset root password

this is the tutorial how to reset your root password. it can be applied to redhat enterprise linux-based (oracle linux, centos, scilinux, fedora ).

1. restart your system, wait until it boot-up. press 'esc' to enter the GRUB menu

2. select from GRUB menu your linux kernel, it usually like this "kernel-vmlinuz-*" , press 'e' to edit

3. edit the at last line (it usually like this "rhgb linux quiet"), change it with :
    rhgb linux single
    or,
    rhgb linux quiet 1
(this two lines above works well with fedora), or
    rhgb linux single init=/bin/bash
(use this line if the previous doesn't work, especially with enterprise-based distribution)
press 'enter' then

4. back to the GRUB menu, choose the kernel and press 'b' to boot

5. wait for the system to boot-up and if the change succeed it will bring the system to login directly as root user

6. type command 'passwd' to enter your new root password

note:
if the last step failed, type the line above on terminal
# mount -n -o remount, rw /
# passwd