The thing that finally made it click for me: compose namespaces named volumes by project name, and that defaults to the folder the compose file sits in. So the same db_data in two stacks ends up as stackA_db_data and stackB_db_data under /var/lib/docker/volumes. Lose track of one and `docker volume inspect ` prints the real Mountpoint. Dockge just makes that layout predictable from the start.