Docker Volumes

Containers are ephemeral.

This means:

when containers are deleted, internal data disappears.

Volumes solve this problem.

Why Volumes Matter

Without volumes:

Container Deleted
       ↓
Data Lost

With volumes:

Container Deleted
       ↓
Data Survives

Volume Example

docker run -v mydata:/data nginx

Breakdown:

Bind Mount Example

docker run -v /host/files:/container/files nginx

This maps:

Host Directory
        ↔
Container Directory

Very common for:

• configs
• media files
• backups
• development work

Listing Volumes

docker volume ls

Inspect volume:

docker volume inspect mydata