Clearing Up Disk Space on Docker Swarm by Removing Unused Data with Prune

After some time, your system can run out of disk space when running a lot of containers / volumes etc. You will find that at times, you will have a lot of unused containers, stopped containers, unused images, unused networks that is just sitting there, which consumes data on your nodes.

One way to clean them is by using docker system prune.

Check Docker Disk Space

The command below will show the amount of disk space consumed, and how much is reclaimable:

$ docker system df
TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              229                 125                 23.94GB             14.65GB (61%)
Containers          322                 16                  8.229GB             8.222GB (99%)
Local Volumes       77                  41                  698MB               19.13MB (2%)
Build Cache                                                 0B                  0B

Removing Unsued Data:

By using Prune, we can remove the unused resources that is consuming data:

$ docker system prune

WARNING! This will remove:
        - all stopped containers
        - all networks not used by at least one container
        - all dangling images
        - all build cache
Are you sure you want to continue? [y/N] y

Deleted Containers:
a3d7db158e065d0c86160fd5d688875f8b7435848ea91db57ed007
47890dcfea4a105f43e790dd8ad3c6d7c4ad7e738186c034d7a46b

Deleted Networks:
traefik-net
app_appnet

Deleted Images:
deleted: sha256:5b9909c10e93afec
deleted: sha256:d81eesdfihweo3rk

Total reclaimed space: 14.18GB

For related Docker posts.