Where can the maximum size and free space for the journal be configured?

The maximum size and free space for the journal in a Linux system using systemd-journald can be configured in the journald.conf file, located in the /etc/systemd/ directory. This configuration file allows administrators to set various parameters for the logging system, including the size of the journal files, how many journal files should be kept, and how much free space should be maintained. This flexibility is essential for managing disk usage effectively while ensuring that the logging system retains necessary data.

Options such as /var/log/journal and /run/log/journal are directories where journal files are stored but are not used for configuration settings. The /etc/rsyslog.conf file is related to a different logging system (rsyslog) that may coexist with systemd's journald but does not configure the journal file's properties. Thus, the appropriate location for configuring journal parameters is indeed the journald.conf file.