Reset RHEL root password

To boot into rescue mode, you must be able to boot the system using one of the following
methods
• By booting the system from an installation boot CD-ROM.
• By booting the system from other installation boot media, such as USB flash devices.
• By booting the system from the Red Hat Enterprise Linux CD-ROM #1.
Once you have booted using one of the described methods, add the keyword rescue as a
kernel parameter. For example, for an x86 system, type the following command at the
installation boot prompt:
linux rescue