pg_test_fsync

pg_test_fsync [options]

pg_test_fsync benchmarks the fsync/flush methods available on the current platform, reporting operations-per-second for each. The results guide the choice of PostgreSQL's `walsyncmethod` (e.g. `fsync`, `fdatasync`, `opensync`, `opendatasync`). Run it on the actual filesystem hosting WAL to get meaningful numbers; cached or virtualized storage will distort results.

-f, --filename file

Test file path.

Seconds per test.

Requires write access to the target directory. Results are affected by caching layers (hardware, virtualization, filesystem) — benchmark on real production storage for accurate comparisons.

pg_test_timing(1), postgres(1)