What all logging goes in /var/log/messages. Where we can apply adjustment to stop unwanted logging in it.
How we can apply retention to it.
You can use "logrotate" kind of standard utility for log retention & rolling.
Following guide provides more detailed information on how you can do so: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/deployment_guide/s2-lo...