F0000FATALTier 1 — Safe✅ HIGH confidence

config file error

Category: Configuration File ErrorVersions: All Postgres versions

🔴 Production Risk Error

High: configuration errors can prevent Postgres from starting or accepting connections after a reload.

What this means

SQLSTATE F0000 is the generic configuration file error code raised when Postgres cannot parse or apply postgresql.conf, pg_hba.conf, or pg_ident.conf. The server may fail to start or a pg_reload_conf() may fail.

Why it happens

1Syntax error in postgresql.conf (e.g., missing quotes, invalid value for a GUC parameter)
2Syntax error in pg_hba.conf (e.g., wrong number of fields, invalid authentication method)
3Syntax error in pg_ident.conf
4Unknown or misspelled GUC parameter name in postgresql.conf

How to reproduce

pg_hba.conf syntax error preventing reload.

trigger — this will ERROR

SELECT pg_reload_conf(); -- fails if config file has errors

FATAL: could not open file "/etc/postgresql/pg_hba.conf": No such file or directory

Fix 1: Validate configuration files before reloading

Before running pg_reload_conf() or restarting Postgres.

fix

-- Postgres 10+ can check the config file:
SELECT * FROM pg_file_settings WHERE error IS NOT NULL;
-- For pg_hba.conf:
SELECT * FROM pg_hba_file_rules WHERE error IS NOT NULL;

Why this works

pg_file_settings and pg_hba_file_rules show any configuration errors without requiring a reload.

Fix 2: Fix the syntax error in the configuration file

When the error identifies a specific line.

fix

Why this works

Edit the configuration file to fix the syntax error identified in the error message. Common issues: missing = sign, invalid boolean value, unrecognised parameter name.

What not to do

✗

Reload or restart Postgres without validating configuration changes

Why it's wrong: A config file error can prevent the server from starting after a restart.

Version notes

Postgres 10+pg_file_settings and pg_hba_file_rules views added in Postgres 10 for pre-reload validation.

Dangerous variant

⚠️ Warning

F0000 after editing postgresql.conf before a restart — server may fail to start

Sources

📚 Official docs: https://www.postgresql.org/docs/current/errcodes-appendix.html

🔧 Source ref: Class F0 — Configuration File Error

Confidence assessment

✅ HIGH confidence

Standard SQLSTATE for configuration file errors. Stable across versions.