How to Use Docker Checkpoint & CRIU for Live Container Migration

Prerequisites

Docker manages container processes; CRIU is integrated in Docker's experimental mode since Docker 1.13. Enable experimental mode by adding {"experimental": true} to /etc/docker/daemon.json and restarting Docker.

$ echo '{"experimental": true}' >> /etc/docker/daemon.json
$ systemctl restart docker

Install CRIU version 2.0 or higher and upgrade the Linux kernel to version 4.3 or newer. Verify the setup with criu check --all and look for the “Looks good” message.

$ criu check --all
Warn (criu/cr-check.c:680): Dirty tracking is OFF. Memory snapshot will not work.
Looks good but some kernel features are missing ...

Build a Sample Docker Image

Create a simple Node program that prints an incrementing number every second.

FROM node
ADD ./app /app
WORKDIR /app
CMD ["node", "index"]

let idx = 0;
setInterval(() => {
  console.log(idx++);
}, 1000);

Build the image:

docker build . -t looper-image

Checkpoint

Run the container and create a checkpoint.

docker run -d --name looper looper-image
docker logs looper   # shows 0 1 2 …
docker checkpoint create looper cp1

After checkpointing the container stops; no logs are produced.

Restore

Restore the same container from the checkpoint: docker start --checkpoint cp1 looper Logs resume from the saved state.

Restore to a New Container or Host

Export the checkpoint directory, copy it to another host, create a new container, place the checkpoint files, and start with --checkpoint=cp1. Logs continue from the saved point.

tar -cvf /root/cp1.tar.gz ./cp1/
scp cp1.tar.gz other-host:/tmp
docker create --name looper-clone looper-image
# extract into /var/lib/docker/containers/<id>/checkpoints
docker start --checkpoint=cp1 looper-clone

Cross‑host migration requires identical environments; CRIU remains experimental for production use.