Information
The journald system includes the capability of compressing overly large files to avoid filling up the system with logs or making the log's size unmanageable.
Note: The main configuration file /etc/systemd/journald.conf is read before any of the custom *.conf files. If there are custom configs present, they override the main configuration parameters
Uncompressed large files may unexpectedly fill a filesystem leading to resource unavailability. Compressing logs prior to write can prevent sudden, unexpected filesystem impacts.
Solution
Edit the /etc/systemd/journald.conf file and add the following line:
Compress=yes