Docker overlayfs Storage Backend

External

• https://docs.docker.com/storage/storagedriver/overlayfs-driver/
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html-single/7.3_Release_Notes/index.html#technology_previews_file_systems

Internal

• Docker Storage Concepts - Storage Backend

Overview

overlay and overlay2 operate at the file level rather than the block level. Because of this, but the container’s writable layer may grow quite large in write-heavy workloads.

Info

At runtime, general statistics on the overlayfs storage driver can be obtained with:

docker info
[...]
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
[...]
Docker Root Dir: /var/lib/docker
[...]