sync(8) on FreeBSD
The text b5e018c51e0e, as FreeBSD 7.0-RELEASE, FreeBSD 6.3-RELEASE, FreeBSD 6.2-RELEASE, FreeBSD 6.1-RELEASE, FreeBSD 6.0-RELEASE shipped it.
force completion of pending disk writes (flush cache)
The text b5e018c51e0e, as FreeBSD 7.0-RELEASE, FreeBSD 6.3-RELEASE, FreeBSD 6.2-RELEASE, FreeBSD 6.1-RELEASE, FreeBSD 6.0-RELEASE shipped it.
force completion of pending disk writes (flush cache)