logs

Contents

Roadmap info from roadmap website

Introduction to Logs

Linux, much like other operating systems, maintains logs to help administrators understand what is happening on the system. These logs document everything, including user’s activities, system errors, and kernel messages. A particularly important time for insightful log messages is during the system boot process, when key system components are loaded and initialized.

The “logs under booting” in Linux refers to the messages and information that are generated during the boot process. These logs record all operations and events that take place while the system is booting, which might assist in diagnosing a system issue or understanding system behavior.

Linux utilizes various log message levels from emerg (the system is unusable) to debug (debug-level messages). During the boot process, messages from various components of the system like kernel, init, services, etc., are stored. Many Linux distributions use systemd logging system, journalctl, which holds the logs of the boot process.

Viewing boot messages can occur in real-time with the dmesg command. It’s used to read and print the kernel ring buffer. Or they can be accessed via the logging setup of your system, which often includes text files in /var/log.

dmesg | less

This command presents the boot logs in a less direct format with the ability to scroll up and down. The kernel ring buffer only has a certain size, so old messages will be discarded after some time.