Which log file mainly stores syslog messages except those linked to authentication and debugging?

The log file that primarily stores syslog messages, excluding those related to authentication and debugging, is /var/log/messages. This file serves as a central repository for logging various system messages and events generated by different services and applications running on the system. It is designed to capture general log entries, encompassing anything from hardware events to system failures and kernel messages, thus providing a comprehensive overview of the system's runtime behavior.

In contrast, other log files have specific purposes: for instance, /var/log/syslog records system-wide messages but can also include some authentication logs depending on the configuration. /var/log/security is typically focused on security-related events, while /var/log/auth.log is specifically concerned with authentication-related log messages, such as user logins and authentication attempts. Therefore, /var/log/messages is the most appropriate choice for general syslog messages not tied to authentication or debugging, as it offers a broader context for system monitoring and troubleshooting.