Why do I get a kernel panic error relating to SELinux when installing X Window System on Centos?

Background

When installing the X Window System on a Centos based instance, you may encounter a kernel panic error similar to this:

audit(1317965535.759:2): enforcing=1 old_enforcing=0 auid=4294967295
Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.
Kernel panic - not syncing: Attempted to kill init!

This is due to the X Window System installing SELinux as a dependency, and if it isn't needed we normally recommend simply disabling it. This article will explain how to do that.

Answer

If you are able to boot and SSH into the instance, you will want to edit the following file:

/etc/sysconfig/selinux

When editing this file, change:

SELINUX=enforcing

to

SELINUX=disabled

Be sure to save the changes and exit the file. Upon reboot, you should no longer see this kernel panic message in the console output.

NOTE: You may not be able to get the instance to a stable enough state where you can edit the /etc/sysconfig/selinux file by SSH. If this is the case, we may need to get creative and setup another instance with a script that can dynamically disable SELinux. Feel free to drop us a line at support@rightscale.com or (866) 787-2253 and we'll be happy to do our best to assist.