[NCLUG] RHEL Upgrade 4.6-4.8

[grant at amadensor.com]

We are looking at upgrading some machines from 4.6 to 4.8.    The
production machines are getting new hardware and need the newer kernel to
work.

Does anyone have a good way to tell what packages or functionality will be
upgraded?   I want to get a good list together of what we need to test
before we let them break production.

I have looked at Red Hat's site, but it only tells me about 3-4, not minor
versions like 4.6 to 4.8.

Has anyone done a similar upgrade?   Anything in particular that went poorly?