Docker disk space cleanup, done in one command!

Whether on Linux or Windows, Docker can accumulate a massive amount of junk files over time!

Today, I learned a command that freed up 30GB of space on my Windows machine in one go!

`docker system prune -a --volumes` is an official, one-click, powerful cleanup command that can instantly free up tens of gigabytes of hard drive space.

*Heads-up: If you're unsure whether you need to keep any volumes, please read the alternative solutions at the end of this article.*

## I. What Does This Command Delete?

This command one-click wipes out **all unused** resources in Docker, specifically including:

- **`-a` (or `--all`)**: Deletes all stopped containers, and **all images not used by running containers** (no longer limited to dangling images).
- **`--volumes`**: Deletes **all data volumes not mounted by any container** (often residual database or application data).
- **Networks and Caches**: Deletes unused networks and build caches.

> ⚠️ **Core Principle**: As long as a container is currently in a **Running** state, the containers, images, and data volumes it depends on will **absolutely not** be deleted.

## II. Risk Warning (Must Read Before Execution)

Before hitting Enter, please confirm:

1. You haven't temporarily stopped (Stop) important containers that you intend to start later.
2. You haven't intentionally left orphaned data volumes (e.g., MySQL data volumes) for future data recovery.
3. **Once deleted, data cannot be recovered!**

## III. Practical Usage Steps

### 1. Check Running Status

First, ensure your important containers are running:

```Bash
docker ps
```

### 2. Execute Cleanup

Enter the command in your terminal:

```Bash
docker system prune -a --volumes
```

### 3. Confirm Execution

The system will pop up a warning and ask for confirmation. Enter **`y`** and press Enter:

```Plaintext
Are you sure you want to continue? [y/N] y
```

### 4. The Results

After the cleanup is complete, the reclaimed space will be displayed at the bottom:

```Plaintext
Total reclaimed space: 14.52GB  # Successfully reclaimed 14.52 GB of space!
```

## Alternative Solutions (Gentler Cleanup)

A gentler approach is to remove some parameters. Here are the specifics:

```Bash
# Only deletes dead containers and dangling images (safest, doesn't delete large images or data)
docker system prune

# Doesn't delete data volumes, only dead containers and unused images
docker system prune -a
```