Intro

Intro

Write and maintain traditional logs: kernel ring buffer, syslog-style messages, and rotation. On systemd systems, pair these with journalctl from Services and runtime.

Commands in this part

Command	Role
dmesg	dmesg prints the kernel ring buffer: hardware detection, driver messages, OOM kills, I/O errors, and other…
logger	logger writes messages to the system log from the shell or scripts.
logrotate	logrotate rotates, compresses, and retires log files so they do not fill disks.

Suggested starting points

1. Kernel messages: dmesg (and journalctl -k).
2. Emit a message: logger.
3. Manage growth: logrotate.

Related parts

• Services and runtime — journalctl
• Text and pipes — mine log files with grep/jq
• Archives and compression — zgrep on rotated .gz logs

Continue with the individual command pages in this part.