Error when trying to build Docker container on external SSD (Ubuntu 22.04.2)

If you are encountering an error while attempting to build a Docker container on an external SSD in Ubuntu 22.04.2, don't worry! This article will guide you through the troubleshooting steps to resolve the issue.

Issue Description

When using Docker on Ubuntu 22.04.2, you may face an error message similar to the following while trying to build a container:

failed to register layer: Error processing tar file(exit status 1): write /path/to/file: no space left on device

Possible Causes

This error typically occurs when the external SSD does not have enough free space to complete the Docker container build process. Docker requires sufficient disk space to store temporary files and build the container image.

Solution

To resolve this issue, follow the steps below:

Check Available Disk Space: Open a terminal and run the following command to check the available disk space on your external SSD:
```
df -h
```
Make sure that the available space on the SSD is greater than the size of the Docker container you are trying to build. If the available space is insufficient, consider freeing up disk space or using a larger external SSD.
Clean Up Docker: Docker may accumulate unused images, containers, and other resources over time. Run the following command to clean up Docker and free up disk space:
```
docker system prune -a
```
This command will remove all unused Docker images, containers, and networks. Confirm the operation by typing 'y' when prompted.
Change Docker Build Location: By default, Docker builds containers in the '/var/lib/docker' directory, which might be on your system's internal storage. To change the build location to your external SSD, follow these steps:
1. Edit the Docker service configuration file by running the command:
```
sudo nano /etc/docker/daemon.json
```
2. Add the following lines to the file and save it:
```
{
            "data-root": "/path/to/external/ssd/docker"
          }
```
  Replace '/path/to/external/ssd' with the actual path to your external SSD.
3. Restart Docker for the changes to take effect:
```
sudo systemctl restart docker
```
Retry Building the Docker Container: After completing the above steps, try building your Docker container again. The error should no longer occur, and the build process should proceed successfully.

Conclusion

By following the troubleshooting steps outlined in this article, you should now be able to resolve the error encountered when trying to build a Docker container on an external SSD in Ubuntu 22.04.2. Ensure sufficient disk space, clean up Docker, and configure the build location to avoid any further issues.

References

Reference	Description
Docker Documentation - docker system prune	Docker command reference for cleaning up unused resources.
Docker Documentation - Docker CLI	Official Docker command-line interface documentation.

Error when trying to build Docker container on external SSD (Ubuntu 22.04.2)