Create data only container:
docker create -v /mongodb_data --name mongodb_data mongo
Create monogdb container:
docker run --volumes-from mongodb_data --name mongo_db --restart always -d mongo
Then to use mongodb in my own container I use the link command:
--link mongo_db:mongo
So everything works fine. Now I want to backup the mongodb according to the docs: http://docs.docker.com/userguide/dockervolumes/#backup-restore-or-migrate-data-volumes and this command:
docker run --volumes-from mongodb_data -v $(pwd):/backup busybox tar cvf /backup/backup.tar /mongodb_data
However the created tar file has just an empty /mongodb_data
folder. The folder contains not a single file.
Any ideas whats wrong? I am using docker 1.7 on ubuntu 14.04 LTS.