On servers hosting Magento websites, MySQL's disk usage will grow extremely fast.
Magento logs to MySQL by default and does not automatically remove log data. This causes the Magento MySQL database to grow each time a user visits the site.
Here is a third-party document discussing how to address this issue.
In that document, running PHP from the command-line is mentioned. Here is a relevant document:
And here is the relevant document for configuring cron jobs: