On digitalocean.com you can find a nice and to the point written introduction to the systemd logging utility journalctl.
Some of the most compelling advantages of
systemdare those involved with process and system logging. When using other tools, logs are usually dispersed throughout the system, handled by different daemons and processes, and can be fairly difficult to interpret when they span multiple applications.
Systemdattempts to address these issues by providing a centralized management solution for logging all kernel and userland processes. The system that collects and manages these logs is known as the journal.
The journal is implemented with the
journalddaemon, which handles all of the messages produced by the kernel, initrd, services, etc. In this guide, we will discuss how to use the
journalctlutility, which can be used to access and manipulate the data held within the journal.
If you are using a modern linux distribution and you need to work with logs – then this may be a good text for you.