Notes from the desk of the operator on bkpdb

What's actually inside your Postgres data directory

Tue, 12 May 2026 00:00:00 +0000

When you install Postgres, run initdb, and start it up, all of your data lives inside one directory. The Postgres documentation calls it “the data directory.” The environment variable points at it: PGDATA. On Debian it’s at /var/lib/postgresql/16/main. On macOS via Homebrew it’s /opt/homebrew/var/postgresql@16. Inside a Docker image it’s wherever the volume is mounted. Wherever you find it, the contents look about the same: a couple of dozen short, cryptic directory names, a handful of config files, and a little file called PG_VERSION that’s there to keep you honest.

Why we restore every backup, every week

Wed, 22 Apr 2026 00:00:00 +0000

Editor’s note. Verified restores are a roadmap feature, not a shipped one. The agent and storage pipeline exist; the scheduled verifier on the control plane does not yet. This essay is the working principle that shapes how we are building it.

For the first six months of bkpdb’s development, we had a perfectly respectable backup pipeline that nobody had ever asked to give anything back. Files appeared in a bucket on schedule. The control plane recorded their sizes and their checksums. The dashboard showed a calm row of green ticks. By every measure we had bothered to define, the product worked.