The mod_security implementation on Plesk 12 is a great new feature but we’ve noticed a tendency to accumulate very large log files at:
This happens on CentOS but not sure if it’s a problem on other distributions.
One way to reduce the logging is to add this line:
Plesk -> Tools & Settings -> Web Application Firewall -> Settings -> Custom directives
Another good step is to add log rotation for the file by creating:
/sbin/service httpd reload > /dev/null 2>/dev/null || true