dockercontainersvolume

Why Docker Failed to remove container-related anonymous volume

Here are my instructions for running the container:

docker run -p 5432:5432 --name=db -e POSTGRES_PASSWORD=secret -d --mount type=volume,src=postgres_data,target=/var/lib/postgresql/data postgres
docker volume ls

Here is the result:

DRIVER    VOLUME NAME
local     postgres_data

And I verify that the container is running properly

And excute the

docker rm --help

command then prompts me that this cmmand can remove the anonymous volume associated with the container:

Options:
  -f, --force     Force the removal of a running container (uses SIGKILL)
  -l, --link      Remove the specified link
  -v, --volumes   Remove anonymous volumes associated with the container

Then I do this:

docker stop db
docker rm -v db
docker ps -a

Here is the result:

CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

Although the container has been removed, the volume is still there and I don't understand why:

docker volume ls

DRIVER    VOLUME NAME
local     postgres_data

how can i remove a container also removes the volume associated with the container

Solution

  • When you remove a container with the docker rm -v command, it will remove the container and any anonymous volumes associated with it. However, named volumes(whichpostgres_data in your case) are not removed by default, even if you use the -v flag.

    Why postgres_data is still there: The volume postgres_data is a named volume, not an anonymous volume. Named volumes are designed to persist data even when a container is removed, and they need to be manually deleted.

    Simply, you can use this command "docker volume rm postgres_data"