podman-system-migrate - Migrate existing containers to a new podman version
podman system migrate [options]
podman system migrate migrates containers to the latest podman version.
podman system migrate takes care of migrating existing containers to the latest version of podman if any change is necessary.
"Rootless Podman uses a pause process to keep the unprivileged namespaces alive. This prevents any change to the /etc/subuid and /etc/subgid files from being propagated to the rootless containers while the pause process is running.
For these changes to be propagated, it is necessary to first stop all running containers associated with the user and to also stop the pause process and delete its pid file. Instead of doing it manually, podman system migrate can be used to stop both the running containers and the pause process. The /etc/subuid and /etc/subgid files can then be edited or changed with usermod to recreate the user namespace with the newly configured mappings.
Set a new OCI runtime for all containers. This can be used after a system upgrade which changes the default OCI runtime to move all containers to the new runtime. There are no guarantees that the containers will continue to work under the new runtime, as some runtimes support differing options and configurations.
April 2019, Originally compiled by Giuseppe Scrivano (gscrivan at redhat dot com)