Docker Storage & Volumes

Data Volumes

• Volumes are files/directories outside of the default Union File System
• Volumes exist as normal directories and files on the host filesystem.

Creating volume

docker container run -d --name mysqlnamedvol -e MYSQL_ALLOW_EMPTY_PASSWORD=TRUE -v mysql-db:/var/lib/mysql mysql

-v : specify new/existing volumes on docker run

Custom drivers & driver options can be specified only if docker volume is created with the volume command. Eg: docker volume create

List volumes

docker volume ls

Bind Mounts

• Maps the host files/directories to a container files/directory i.e. Two locations pointing to the same files.
• Bind mounts cannot be used in Dockerfile, must be used at container run
• Bind mount starts as / whereas volume mount starts without

Mac/Linux:

... run -v /Users/mhs/stuff:/path/container

Windows:

... run -v //c/Users/mhs/stuff:/path/container

How docker differentiates between volumes & bind mounts?

Bind mounts start with a/ in linux & // in windows.