When you forget your root password there is a way to reset root password

first you have to power on a virtual machine or your RedHat Linux machine. When the bootloader menu appears press any key to pause the booting process then select the kernel using the arrow keys

then press letter ‘e ‘ key to go on edit mode

then go to the line that starts linux16 then go along with that line there is keyword ro change that to rw .

And also remove these keywords from that line “console=tty0′ & ‘console=ttyS0,115200n8” Otherwise this prossess will hang

Then come again to the beginning of the linux16 line and press the end key on the keyboard this will move the cursor to the end of that line. At the end add rd.break

Then press ctrl+x for a boot with newly configured settings

Now it will work without hanging

This will boot in to switch_root prompt

switch_root:/# mount -oremount,rw /sysroot

switch_root:/# chroot /sysroot

Now you can change the root password to anything you like.I’m changing my password to sameera

sh-4.2# echo sameera | passwd --stdin root

Then type sh-4.2# touch /.autorelabel

This will relabel all the file systems with SELinux again

Then type exit and again type exit.

Now your RedHat machine is with new root password