Docker Data Volume Container - Can I share across swarm

Question

I know how to create and mount a data volume container to multiple other containers using --volumes-from, but I do have a few questions regarding it's usage and limitations:

Situation: I am looking to use a data volume container to store user uploaded images in for my web application. This data volume container will be used/mounted by many other containers running the web frontend.

Questions:

1. Can data volume containers be used/mounted in containers residing on other hosts within a docker swarm?

2. How is the performance? is it recommended to structure things this way?

3. Is there a better way to handle sharing of persistent resources across containers and hosts such as NFS?

Answer 1

Can data volume containers be used/mounted in containers residing on other hosts within a docker swarm?

Docker, by itself, does not provide any facility for either migrating data or sharing data between hosts in a cluster.

How is the performance? is it recommended to structure things this way?

Docker volumes impose very little performance overhead in general, because they're just bind mounts.

Is there a better way to handle sharing of persistent resources across containers and hosts such as NFS?

NFS or any cluster filesystem, such as gluster, can be used to create data volumes that are available to all hosts in a cluster.

Answer 2

There is a technology called as Flocker which will help you to move your containers across the hosts with the attached volume. Flocker is open source. Docker in itself doesn't provide any functionality for Docker container migration. There is a small article on container migration. Hope it will be helpful.