Course
data-engineering-zoomcamp
Question
Why does Postgres fail to start after upgrading from postgres:16 to postgres:18
Answer
Postgres 18 changes how database data directories are structured inside Docker containers. While Postgres ≤16 stored data under /var/lib/postgresql/data, Postgres 18 expects the volume to be mounted at /var/lib/postgresql. If an existing volume created with an older Postgres version is reused without updating the mount path, Postgres 18 will detect an incompatible layout and exit during startup. This can appear as DNS resolution errors or failed connections from pgAdmin or ingestion jobs. For Week 1 setups, the fix is to update the volume mount path, remove the old volume, and recreate the containers so Postgres 18 can initialize a new data directory.
Checklist
Course
data-engineering-zoomcamp
Question
Why does Postgres fail to start after upgrading from
postgres:16topostgres:18Answer
Postgres 18 changes how database data directories are structured inside Docker containers. While Postgres ≤16 stored data under
/var/lib/postgresql/data, Postgres 18 expects the volume to be mounted at/var/lib/postgresql. If an existing volume created with an older Postgres version is reused without updating the mount path, Postgres 18 will detect an incompatible layout and exit during startup. This can appear as DNS resolution errors or failed connections from pgAdmin or ingestion jobs. For Week 1 setups, the fix is to update the volume mount path, remove the old volume, and recreate the containers so Postgres 18 can initialize a new data directory.Checklist