Updating to FC7 from FC6 via Yum?

[Philip Prindeville]

Is it reasonably safe to update a running system via Yum a major version?

And is there a particular way to do it?  Do I need to grab new 
/etc/yum.d/ files?

Or am I better off burning a DVD, and rebooting off that, and selecting 
"upgrade"?

Because there are some remote machines that don't have DVD readers, and 
it would make my life a lot simpler if I didn't have to go and visit 
them, physically plug in a USB DVD driver, reboot, upgrade, and then 
reboot again...

-Philip