SELinux
Security-Enhanced Linux (SELinux) is a Linux feature that provides a mechanism for supporting access control security policies, including U.S. Department of Defense style mandatory access controls, through the use of Linux Security Modules (LSM) in the Linux kernel.en.wikipedia.org/wiki/Security-Enhanced_Linux
Toolpack and SELinux
The Toolpack software doesn't support SELinux. Enabling it while Toolpack is running will lead to unexpected behavior.