How to migrate a single container from one server to another server?

Docker Engine General
1

Hi experts,

Server 1
Server 2

On server 1 I have a container running abc and I would like to copy the container to Server 2. Is it possible?

  1. Is it possible to do it using docker checkpoint?
  2. Is it possible to cold migrate the docker container to another server?
  3. Is it possible to live migrate to another server?
2

A container is a temporary isolated environment where we don’t even save anything that has to be migrated. If you did that, you will need to switch to the right way eventually, which is using volumes or bind mounted folders for persistent storage. Then you can move the data the way you would without containers and just recreate the container on a new server by running the same command you did on the original server.

You can choose copying out data from the container (docker cp --help) even when the container is stopped but not removed and changing the container definition to mount that folder on the new server

Or you can run docker container commit to make an image from the container, use docker image save to save that image, copy the tar file to the new server, and use docker image load on the new server. You will also need to change the command you used to create the container, because you will have a new image with a new name.

But again, the right way is not storing data in the container. So even if you don’t want to do it now, don’t forget about it.

3

To address your bullet points:

  1. Checkpoint is used for point in time checkpoints of a container, so this container can be restored at any existing checkpoint.
  2. option a) manually (see @rimelek’s answer). option b) Docker swarm services can be used to run containers that could be spawned on other nodes, if the node they are running becomes unavailable. Volumes would need to use remote shares accessible by all nodes where the container could be potentially spawned.
  3. Not possible. It is possible for Kubernetes, though it requires a commercial product cast.ai
5

Thanks a lot @rimelek for anwering for my question.

We are running some HPC worloads unlike normal applications.

I was trying to explore if we can do live migration of the container like we do it for VMs using virsh in kvm based.

or in worst case to do cold migration.