How to solve the issue of deleted files not releasing space in Docker

When deleting files using Docker, the files do not actually immediately release disk space. This is because Docker images and containers are layered, so when deleting files, it only removes the corresponding layer instead of directly deleting the file on the disk.

To solve this problem, you can use the following methods:

1. Clean up unused images and containers: Use the ‘docker image prune’ and ‘docker container prune’ commands to clean up unwanted images and containers, which will delete any unused ones, thereby freeing up disk space.
2. Clean up useless volumes: Use the Docker volume prune command to remove unused volumes, freeing up disk space.
3. Compressing image layers: Export the image as a tar file using the docker image save and docker image load commands, and then re-import it. This will compress the image layers and free up disk space.
4. Regularly clean up unused images and containers: You can schedule a regular task to use the above command to clean up unused images, containers, and volumes to prevent disk space from being occupied for a long time.

Please note that these methods are temporary solutions. If your images and containers continue to grow, you may need to reevaluate your storage strategy, such as using Docker volumes or external storage to manage data.