CentOS hangs on startup after yum update
Usually it will hang after Starting certmonger: [OK]
Startup the hanging machine (H1)
From another machine do:
> ssh H1
> mv /etc/X11/xorg.conf /etc/X11/xorg.conf.bak
Now restart H1.
You can have more explanations by doing a “tail -n 200 /var/logXorg.0.log” on the hanging machine.