I have a docker volume defined in my docker-compose.yml

version: "2"
services:
  postgres:
    image: my_image/postgresql:9.3
    volumes:
      - test_volume:/var/lib/postgresql/data
    ports:
      - "5432:5432"
volumes:
  test_volume: 

I want to know what is the standard way of backing up data from server?

Ideally I would like to just move docker volume around the servers, like from my production server to my sandbox server.

Or do people usually just dump the backup sql file and move it to somewhere else through automation tool?