UniFi Controller Data Partition Nearly Full

I have the Unifi controller running in a docker container. The volume hosting all my containers only uses 20% of it’s allocated space. I received an email from the controller saying “Message: The UniFi Controller data partition is nearly full. Only 403333120 of 15785205760 bytes free”

Why does the controller think it’s running out of space? How can I fix this?

Thanks

You need to provide us with more info…
How have you deployed the container? what parameters did you use to deploy? (code snippets or screenshots) - Host os info.