Why does docker take up more and more space?

  docker, question

I have several images, which add up to about 2.3G, many of which are based on the same image.
Now each mirror runs a container
I find
/var/lib/doc/containers has 5.1G
/var/lib/doc/vfs 17G
/var/lib/doc/volumes 10G

I have solved the problem of/var/lib/doc/volumes space occupation through doc volume rm $ (doc volume ls-qfdangling = true)

I went into/var/lib /var/lib/docker/containers to check the size, and found that there was a directory of 5.1G and the others were 28K, so I knew which container was by name, so I went into the container to calculate the size of the entire root directory, and found that there was only more than 200 m. what file should I delete to free up space?

The other is that the/var/lib/doc/VFS directory does not know how to free up space

Excuse me, have you solved the problem?