Docker Community Forums

Share and learn in the Docker community.

Docker on ZFS thinks almost all volumes are dangling

Hello. I want to prune unused volumes but I cannot at the moment since docker thinks almost all volumes are unused, which is false.

I am running Docker version 19.03.8, build afacb8b on CentOS 8.1 with ZFS 0.8.3.
Docker is configured to use the ZFS driver and is doing so properly, by creating a dataset for each volume (each image layer etc.)

After a 4 month period I want to prune unused images and volumes since there are now hundreds of datasets that are not needed.

I am currently running 25 containers, 23 through docker-compose and 2 through docker run.

docker volume ls --filter "dangling=false"
shows only 6 volumes while
docker volume ls
shows 123. Docker thinks that 117 volumes are not being used, which is obviously incorrect.

What is the problem here?