Got this advice from a CTO – hot topics for system administrators:
1. performance monitoring
2. capacity planning
3. virtualization
4. Disaster recovery(DR) planning

By default, any error message in your php script will be visible to site visitors on the browser and will be logged to apache error log file – most commonly in “/var/log/httpd/error.log”. In a production server it is advisable to prevent the error message from appearing on browser and has to be silently sent to a custom log file, specifically created for logging only php error messages. Following these steps might help:

1. Create the file under /var/log –

$touch /var/log/php-error.log

2. change permission to 644 –

$chmod 644 /var/log/php-error.log

3. set ownership –

$chown root.apache /var/log/php-error.log

(if httpd is running under apache, could be www-data, nobody…)

4. Edit /etc/php.ini  and make sure the following options are set correctly

error_reporting = E_ALL
display_errors = OFF
error_log =/var/log/php-error.log
log_errors = ON

5. Write a php script with some syntax error in it and check whether the error notification is logged or not

$tail -f /var/log/php-error.log