[keycloak-user] volume for hdb content of container?

Hello, I am experimenting with keycloak using https://hub.docker.com/r/jboss/keycloak and default database, i.e. h2. Is there a means to have h2 persist the database to a file on a docker volume and load at startup instead of starting configuration from scratch? My environment does not need to support lots of users and afai understood the database is primarily for configuration when not replication ldap users. Using any of the other databases looks overkill to me. Or if that perception is wrong, I am wondering why my configuration was lost after trivial reconfiguration of my docker-compose.yml.. Any suggestion? Thanks, Joachim