Followed the information I found, I added graphroot and driver to /etc/containers/storage.conf. Then removed the default location folder. Ran podman with root and storage-driver parameters. Then podman info with no parameter. At this moment, it showed correctly about the new graphRoot.
But then I ran podman info again, and it returned to default location. Same thing happened with rootless.
What steps should I take? It is podman 2.0.4 on NixOS.