Save / restore

VM

Create a VM.

# Replace the path in vm.xml with an absolute one and create the VM.
sed "s|\$IMAGES|$(pwd)/images|g" vm.xml | \
sed "s|\$QEMU|$(which qemu-system-x86_64)|g" | \
virsh create /dev/stdin

Domain 'vm' created from /dev/stdin

virsh list --all

 Id   Name   State
----------------------
 1    vm     running

Create a snapshot of the VM.

mkdir -p $PWD/snapshots
virsh dumpxml --migratable --domain vm > snapshots/snapshot.xml
virsh save --domain vm --xml snapshots/snapshot.xml --file snapshots/snapshot.saved

Domain 'vm' saved to snapshots/snapshot.saved

Check the VM status.

virsh list --all

 Id   Name   State
----------------------

Restore the snapshot.

virsh restore --xml snapshots/snapshot.xml --file snapshots/snapshot.saved --running

Domain restored from snapshots/snapshot.saved

Check the VM status.

virsh list --all

 Id   Name   State
----------------------
 2    vm     running

Connect to the VM.

virsh console vm

#OR

docker run -ti -e NOVNC_PORT="8080" -e VNC_SERVER_PORT="5900" -e VNC_SERVER_IP="host.containers.internal" -p 8080:8080 voiselle/novnc

Disconnect from the VM with ctrl + 5 (macOS).

Cleanup.

virsh destroy vm

Docker

Setup Docker:

cat <<EOF > /etc/docker/daemon.json
{
  "experimental": true
}
EOF

sudo systemctl restart docker

Create snapshot:

docker run -di --name ubuntu ubuntu

docker exec -ti ubuntu bash
# -> apt update && apt install -y tmux vim
# -> tmux
# -> tmux set -g status off
# -> vim
# -> type something in buffer
# -> detach tmux (ctrl+b d)
# -> exit container (ctrl + d)

mkdir -p $PWD/checkpoints
docker checkpoint create --leave-running --checkpoint-dir $PWD/checkpoints ubuntu first
docker stop ubuntu

Check.

docker ps

CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

docker checkpoint ls --checkpoint-dir $PWD/checkpoints ubuntu

CHECKPOINT NAME
first

Restore snapshot:

# Work around a docker bug https://github.com/moby/moby/issues/37344
cp -R $PWD/checkpoints/first /var/lib/docker/containers/$(docker ps -aq --no-trunc --filter name=ubuntu)/checkpoints/

docker start --checkpoint first ubuntu

docker exec -ti ubuntu tmux a

The state is exactly the same as we left it before the checkpoint/restore.

Podman

NOTE: For some reason networking doesnt work after restore, so that still needs to be figured out.