Often times, I employ a CentOS VirtualBox virtual machine (VM) as a development, testing and staging environment, I love the flexibility of virtual environments for testing and development work before moving my work to production environments.
Recently I ran a yum update and yum upgrade on a CentOS 6.4 VM and subsequently rebooted it, only to be greeted by a blank screen following bootup. A quick search of virtual TTY terminals yielded a login prompt.
Search of the usual logs (/var/log/messages and /var/log/dmesg) did not yield anything useful, however, the /var/log/Xorg.0.log displayed some interesting messages. Of particular interest were;
"... (EE) Failed to load module "vboxvideo" (module requirement mismatch, 0)"
... (EE) No drivers available."
Fatal server error:"
... no screens found"
A bit of Google revealed "http://www.centos.org/modules/newbb/print.php?form=1&topic_id=41799&forum=55&order=ASC&start=0" So I followed suit and backed up the /etc/X11/xorg.conf file and rebooted :) All is well...