One of the most common surprises after working with Docker on a VPS is how quickly disk space disappears.

You may not deploy many containers, logs look reasonable, and df -h still shows free space — yet Docker suddenly refuses to pull a new image with a familiar error: no space left on device.

These Docker disk space issues on VPS environments rarely come from a single obvious mistake. Instead, they are usually the result of how Docker stores data internally and how small VPS disks behave under container workloads.

For many users, the problem starts shortly after they install Docker on Ubuntu 24.04 and begin testing containers. A few images are pulled, some containers are started and stopped, maybe a test build fails. Nothing seems unusual.

Then disk usage jumps unexpectedly.

This happens because Docker is designed to favor speed and reuse over minimal disk usage. On a VPS with limited storage, that trade-off becomes visible very quickly.

The natural reaction is to assume that a running container is consuming all available disk space. Users often start checking application directories, mounted volumes, or log files inside containers.

In many cases, none of these explain the problem.

The real issue is that Docker disk usage is spread across layers, images, and internal metadata that are not immediately visible from the container level.

By default, most Linux VPS setups use Docker with the overlay2 storage driver.

This means that every image layer, writable container layer, and cached build artifact is stored on disk under Docker’s data directory, usually:

Important details often overlooked:

  ● Pulled images remain on disk even if no container uses them

  ● Failed or partial builds leave layers behind

  ● Stopped containers still occupy space

  ● Deleted containers may leave unused layers

  ● Volumes persist unless explicitly removed

This is why checking filesystem usage alone is not enough.

The df -h command reports total filesystem usage. Docker, however, manages its own internal objects within that filesystem.

As a result, df -h can show that disk space is almost full without explaining why.

To understand Docker disk usage, this command is far more useful:

It shows how much space is used by:

  ● images

  ● containers

  ● volumes

  ● build cache

  ● reclaimable data

For many VPS users, this is the first moment when the real source of disk consumption becomes clear.

In practice, disk space on a VPS is usually consumed by a combination of factors rather than a single cause.

Common contributors include:

  ● unused or outdated images

  ● dangling layers from failed builds

  ● stopped containers

  ● persistent volumes

  ● continuously growing container logs

Logs are especially dangerous on small VPS plans. Without log rotation, a single container can silently consume several gigabytes over time.

Before removing anything, it is important to understand what Docker considers unused.

Start with:

If Docker reports a significant amount of reclaimable space, the following command is generally safe:

This removes:

  ● stopped containers

  ● unused networks

  ● dangling images

  ● build cache

It does not remove running containers or named volumes.

However, this should be viewed as cleanup, not a permanent fix.

Running docker system prune can free space, but it does not change Docker’s behavior. If your workflow involves frequent image pulls, rebuilds, or CI jobs, disk usage will grow again.

On VPS plans with 20–30 GB of storage, Docker will always feel constrained. This is not a misconfiguration — it is a limitation of disk size combined with Docker’s caching model.

Long-term solutions usually involve:

  ● increasing disk capacity

  ● limiting image retention

  ● configuring Docker log rotation

  ● separating build environments from production containers

In some cases, disk space remains low even after Docker cleanup.

Other common VPS-related causes include:

  ● automatic snapshots

  ● backup agents

  ● system journal growth

  ● provider-level disk reservations

Docker is often blamed because it is visible and easy to inspect, while these other factors are not.

Docker disk space issues on VPS platforms are rarely caused by a single mistake. They are usually the result of Docker’s storage model meeting limited VPS resources.

You can clean up unused data and delay the problem, but on small disks it will eventually return.

Understanding where the space goes — and why — is far more effective than repeatedly reacting to “disk full” errors.