Storage driver options in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Docker storage driver?

A Docker storage driver manages how images and containers store and share data on the host system's filesystem.

beginner

Name two common Docker storage drivers.

Overlay2 and aufs are two common Docker storage drivers used to manage container file systems.

intermediate

Why might you choose the overlay2 storage driver over aufs?

Overlay2 is preferred because it is simpler, faster, and supported by most modern Linux kernels, while aufs may require extra setup.

intermediate

How do you specify a storage driver when starting the Docker daemon?

You specify it with the --storage-driver option in the Docker daemon configuration or command line, for example: dockerd --storage-driver=overlay2

advanced

What happens if you change the Docker storage driver on an existing system?

Changing the storage driver can cause existing images and containers to become unusable because each driver uses a different format for storing data.

Which Docker storage driver is recommended for most modern Linux systems?

A devicemapper

B btrfs

C overlay2

D vfs

Overlay2 is the default and recommended driver for most modern Linux kernels due to its performance and stability.

What command option sets the storage driver for the Docker daemon?

A --storage

B --driver-storage

C --driver

D --storage-driver

The correct option is --storage-driver to specify which storage driver Docker should use.

What is a risk of switching storage drivers on a Docker host with existing containers?

A Containers may stop working due to incompatible storage formats

B Docker will automatically migrate all data safely

C No impact, containers continue as normal

D Docker will delete all images automatically

Switching storage drivers can break existing containers because each driver stores data differently.

Which storage driver uses a copy-on-write mechanism to save space?

A overlay2

B vfs

C devicemapper

D none

Overlay2 uses copy-on-write to efficiently share files between containers.

If your Linux kernel does not support overlay2, which driver might you use?

A vfs

B aufs

C zfs

D overlay2

Aufs is an alternative storage driver used when overlay2 is not supported by the kernel.

Explain what a Docker storage driver does and why it matters.

Think about how Docker saves container data on your computer.

Describe the steps to change the Docker storage driver and what precautions you should take.

Changing storage drivers is like changing how your files are saved; it needs care.