I am trying to run a 'yum upgrade', and it all works fine until:
Test transaction complete, Success!
<first package> 100 % done 1/1223
then it hangs, and I have to kill the process.
When I try again, same story. It installs one package and hangs.
I tried to boot from CD and upgrade, same thing there.
When it actually starts installing packages, it reboots.