postgres containers share pgdata mount

Due to an oversight, we have 3 postgres containers (docker) all mounting the same pgdata directory. In essence this means 3 postgres instances are running over the same pgdata.

I imagine this would create issues, but it seems to have been working so far, should I be concerned (I'm very new to postgres & containers)

I see 2 options:

1. Only start 1 postgres container and link all consuming containers (makes more sense to me). If 1 postgres instance is overloaded, set up a proper cluster instead


2. Create separate data directory for each container and start the container with this volume mounted