Does anyone have GRSecurity kernel installed correctly on Centos 6.3? If so please advise what kernel version you used and what settings / config file did you use while compiling it? I recently tried to install the latest kernel from grsecurity using this guide: SecurityTargets Blog: Hardening CentOS kernel with grsecurity Using this kernel: grsecurity-2.9.1-3.2.31-201210111928.patch and it compiled and installed ok but won't boot from it, it just falls back to the previous kernel installed and listed in the boot configuration. Is that kernel compatible with Centos 6.3 or do I need to use the grsecurity-2.9.1-18.104.22.168-201210111928.patch version? Also once that is figured out, then the question is what settings to use during the compilation, i copied this file, config-2.6.32-279.9.1.el6.x86_64, from my /boot/ to start from. Anyone with experience with installing and configuring GRSecurity on a cPanel / Centos 6.3 system, please help.