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Docker images and volumes

Images and volumes use disk space silently. The Images and Volumes pages show what is used by which container, and what can be removed.

Images

Section titled “Images”

The Images page lists every image with its identifier, size, creation date and use. The use column states which containers use an image, or marks it as unused or dangling. A dangling image has no tag. It is usually an old build that a new one has overwritten, and no container uses it. The footer states the total size, the part that is dangling and the part that is unused.

Prune images

Section titled “Prune images”

Prune images opens a dialog with two choices.

The Prune images dialog with the choice Dangling images only (safe) selected, the list of images that would be removed, the size that would be reclaimed, the command docker image prune -f, and the buttons Cancel and Remove 1 image.
Figure 1. The Prune images dialog.
Choice Effect
Dangling images only (safe) Removes untagged images that no container uses
All unused images Also removes tagged images that no container uses. These can be the images that are needed to roll back, so the dialog warns about it

The dialog lists the images that would be removed, the space that would be reclaimed and the exact command. Volumes are not removed.

Volumes

Section titled “Volumes”
The Volumes page with three volumes, each showing its path, its size and the container it is mounted in, or Not mounted.
Figure 2. The Volumes page.

The Volumes page lists the volumes with their path on the server, their size and the container that mounts them. Sizes are calculated on the server and can take a few seconds. A volume that is mounted nowhere is shown as Not mounted.

The menu of a volume copies its path or removes it. The page itself is read-only.

Remove a volume

Section titled “Remove a volume”

Removing a volume deletes all of its data permanently. The dialog states the size of the data, says that it cannot be undone, and requires typing the name of the volume. A volume that is mounted in a container cannot be removed. The dialog names the container, and the container must be stopped and removed first.