Docker Volume

In this tutorial, you’ll learn how to inspect, remove, prune, and configure Docker volumes. Managing volumes effectively helps persist data across container lifecycles and keeps your host system clean.

Table of Contents

• Inspecting a Volume
• Removing a Volume
• Pruning Unused Volumes
• Verifying Mount Options
• Mounting a Volume as Read-Only
• References

Inspecting a Volume

Use docker volume inspect to retrieve metadata about your volume, including driver, mount point, labels, and scope:

docker volume inspect data_volume

Sample output:

[
  {
    "CreatedAt": "2020-01-20T19:52:34Z",
    "Driver": "local",
    "Labels": {},
    "Mountpoint": "/var/lib/docker/volumes/data_volume/_data",
    "Name": "data_volume",
    "Options": {},
    "Scope": "local"
  }
]

This command is essential for troubleshooting mount permissions and verifying where Docker stores your volume data on the host.

Removing a Volume

To delete a volume that’s no longer used by any container:

docker volume rm data_volume

If the volume is active, Docker returns an error:

Error response from daemon: remove data_volume: volume is in use - [2be4d9182296…]

Stop or remove the container first, then run the same command again:

docker volume rm data_volume
# data_volume

Pruning Unused Volumes

Clean up all dangling volumes in one step to free up disk space:

docker volume prune

You'll see a confirmation prompt:

WARNING! This will remove all local volumes not used by at least one container.
Are you sure you want to continue? [y/N] y
Deleted Volumes:
  data_vol3
  data_vol1
  data_vol2
Total reclaimed space: 12MB

Verifying Mount Options

By default, volumes are mounted read-write. To inspect a container’s mount configuration:

docker container inspect my-container

Look for the Mounts section:

"Mounts": [
  {
    "Type": "volume",
    "Name": "data_vol1",
    "Source": "/var/lib/docker/volumes/data_vol1/_data",
    "Destination": "/var/www/html/index.html",
    "Driver": "local",
    "Mode": "z",
    "RW": true,
    "Propagation": ""
  }
]

Mounting a Volume as Read-Only

To ensure data integrity, you can mount a volume as read-only. Use the --mount flag with readonly:

docker container run \
  --mount type=volume,source=data_vol1,target=/var/www/html,index.html,readonly \
  httpd

This is useful for scenarios where containers should not modify shared data.

Common Docker Volume Commands

References

• Docker Volumes Overview
• Use Bind Mounts or Volumes
• Docker CLI Reference