title: Reclaim disk space after removing file from Docker container
body: <p>I've successfully copied a large database backup file (35 GB) into the Docker container and restored my database locally (following <a href="https://database.guide/how-to-restore-a-sql-server-database-on-a-mac-using-sql-operations-studio/" rel="noreferrer">this walkthrough</a>). I want to now delete that .bak file from the Docker container to reclaim the space. I did that by running <code>sudo docker exec sql_server rm -rf /var/opt/mssql/backup/example.bak</code> but this didn’t reclaim the space - my Docker.raw file remains about 76 GB. When I run <code>docker system df</code> it says my containers are 45 GB though. I tried <code>docker system prune -a</code> but this reclaimed 0B. Restarting Docker didn't do the trick. How do I shrink that now that the file is removed in order to gain that space back?</p>