Exactly. From the big fat warning box at the top of the page: > Red Hat does not support in-place upgrades between any major versions of Red Hat Enterprise Li

Exactly. From the big fat warning box at the top of the page: > Red Hat does not support in-place upgrades between any major versions of Red Hat Enterprise Linux. A major version is denoted by a whole number version change. For example, Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6.5 are both major versions of Red Hat Enterprise Linux.