Enhancement to enable the automatic deletion of the /var/log/journal/ directory, as it significantly contributes to disk usage when the disk is full, and no automatic deletion occurs.

Testing Steps:

1. Copy several large files into the /var/log/journal directory.

2. Log in as the root user and run df -h to check the disk usage percentage for the /var directory.

3. If the usage exceeds 75%, the files within /var/log/journal/ will be automatically deleted.