PG_TEST_FSYNC(1) PostgreSQL 18.6 Documentation PG_TEST_FSYNC(1) NAME pg_test_fsync - determine fastest wal_sync_method for PostgreSQL SYNOPSIS pg_test_fsync [option...] DESCRIPTION pg_test_fsync is intended to give you a reasonable idea of what the fastest wal_sync_method is on your specific system, as well as supplying diagnostic information in the event of an identified I/O problem. However, differences shown by pg_test_fsync might not make any significant difference in real database throughput, especially since many database servers are not speed-limited by their write-ahead logs. pg_test_fsync reports average file sync operation time in microseconds for each wal_sync_method, which can also be used to inform efforts to optimize the value of commit_delay. OPTIONS pg_test_fsync accepts the following command-line options: -f --filename Specifies the file name to write test data in. This file should be in the same file system that the pg_wal directory is or will be placed in. (pg_wal contains the WAL files.) The default is pg_test_fsync.out in the current directory. -s --secs-per-test Specifies the number of seconds for each test. The more time per test, the greater the test's accuracy, but the longer it takes to run. The default is 5 seconds, which allows the program to complete in under 2 minutes. -V --version Print the pg_test_fsync version and exit. -? --help Show help about pg_test_fsync command line arguments, and exit. ENVIRONMENT The environment variable PG_COLOR specifies whether to use color in diag- nostic messages. Possible values are always, auto and never. SEE ALSO postgres(1) PostgreSQL 18.6 2026 PG_TEST_FSYNC(1)
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=pg_test_fsync&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>