Your new Centos 6.x server will quickly build up logs and the php.ini log is one that can get huge. If you only want to see real errors then you need no more than the following setting in your php.ini.
Edit your current PHP.INI
nano /etc/php.ini
Replace the error_reporting setting as follows
error_reporting = E_COMPILE_ERROR|E_ERROR|E_CORE_ERROR
In the even that you require a less strict log level, you can change the entry when required, debug your session then promptly change it back.