Reset root Password on Red Hat/CentOS 7

1. First you should physically near the server for direct access :) and reboot the server. Then interrupt the boot by pressing any key. You will get a screen like follows.

2. Press 'e' to edit and add "rd.break" to the end of the linux16 line. Then press "Ctril X" to start.

You will get a screen like follows...

3. Mount "/sysroot" with read/write permissions.

#mount -o remount,rw /sysroot    

4. Switch into chroot jail. Set /sysroot as the root

#chroot /sysroot  

5. Set password for root.
#passwd root

6. Enable selinux

#touch /.autorelabel                       

7.end :)
#exit