Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux

Chapter 4. General Updates

In-place upgrade from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7

An in-place upgrade offers a way of upgrading a system to a new major release of Red Hat Enterprise Linux by replacing the existing operating system. To perform an in-place upgrade, use the Preupgrade Assistant, a utility that checks the system for upgrade issues before running the actual upgrade, and that also provides additional scripts for the Red Hat Upgrade Tool. When you have solved all the problems reported by the Preupgrade Assistant, use the Red Hat Upgrade Tool to upgrade the system.
Note that the Preupgrade Assistant and the Red Hat Upgrade Tool are available in the Red Hat Enterprise Linux 6 Extras channel, see (BZ#1432080)