[Podman] Re: Including file system changes in container migration

The current container migration implementation in Podman cannot handle changes to the file-system. If a container changes a file the recommendation is to mount that directory as a tmpfs and then the changed file will be correctly migrated to the destination system. If something changes a file in /tmp for example, following steps are currently necessary: # podman run -d --tmpfs /tmp <container> # podman container checkpoint -l -e /tmp/chkpt.tar.gz # scp /tmp/chkpt.tar.gz destination-host:/tmp On the destination host of the migration: # podman container restore -i /tmp/chkpt.tar.gz Files changed in /tmp in the container will also be in the restored container on the destination host, because CRIU automatically handles tmpfs directories. To make it easier for users to not have to mark all changed directories as --tmpfs I would like to include changed files in the checkpoint archive (/tmp/chkpt.tar.gz from my example). One possible implementation could use vendor/github.com/containers/storage/store.go: // Diff returns the tarstream which would specify the changes returned // by Changes. If options are passed in, they can override default // behaviors. Diff(from, to string, options *DiffOptions) (io.ReadCloser, error) This sounds exactly like what I need. I get a tarstream which I can embed into the checkpoint archive and which can then be used with ApplyDiff() before restoring the container. Does this sound like the right approach to also migrate file-system changes during container migration? Adrian