When performing a Docker Trusted Registry (DTR) metadata backup, which of the following is not included in the backup?

The correct answer pertains to the nature of what Docker Trusted Registry (DTR) backups are designed to include. When performing a metadata backup, it primarily captures configuration information involving the registry itself, such as repository details, user permissions, and registry configurations.

Docker images, on the other hand, are stored in a different section of the Docker ecosystem and represent the containerized applications that are built from the images. Images reside on storage backends rather than being part of the metadata that the backup process focuses on. Therefore, while the backup captures how the registry operates and the permissions granted to users, the actual container images are stored separately and would not be included in this specific metadata backup process.

Understanding this distinction is key, as it highlights the difference between registry configuration and the lifecycle management of images themselves, which is essential for effectively managing a Docker Trusted Registry.