Maybe https://forum.cloudron.io/topic/1579/var-lib-docker-overlay2-getting-full?_=1760112116784 is helpful:
@nebulon said in /var/lib/docker/overlay2 getting full:
For a start, docker images are often quite large, composed of a multitude of filesystem layers on top of each other. To mitigate the problem a bit, all Cloudron apps share the same base image, that helps a bit. The appsdata folder really only contains the data from within the apps, so that heavily depends on your own usage. The application code, so to speak, is inside those docker images.