Persisting PostgreSQL data on host

Option A, host bind mount

best for direct host access and backups

• Mount a host directory to the container’s data dir (usually /var/lib/postgresql/data)
• Pros: you can back up/edit files directly on the host; easy to inspect.
• Cons: host permission must align with the postgre user inside the container; slightly more OS-specific concerns.

Example(Linxu):

• Prepare host dir: mkdir -p /host/postgre-data; chwon 999:999 /host/postgre-data
• Run: docker run –name my-postgres -e POSTGRES_PASSWORD=secret -e POSTGRES_DB=mydb -v /host/postgres-data:/var/lib/postgresql/data -p 5432:5432 -d postgres:15

Option B, Docker named volume

best for Docker lifecycle management

1. Use a named volume to store data (still persists beyond container life; data lives on the host, but managed by Docker)
2. Pros: easier to manage, fewer permission issues, better protability.
3. Cons: you don’t directly browse host files unless you inspect the volume.

Example:

• Create and run:
  • docker volume create pgdata
  • docker run –name my-postgres -e POSTGRES_PASSWORD=secret -e -v pgdata:/var/lib/postgresql -p 5432:5432 -d postgres:15

Where data is stored on host:

docker volume inspect pgdata

Create a database: