It's more correct to use O_DSYNC in addition to O_DIRECT. This adds FUA to the disk write if the disk requires it for durability.

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thomas_fa 3 days ago | parent [-]

Yes, that has also been pointed out in other threads. Yes this could be very important settings, and even some of common Linux file systems actually don't do that every time and we need to disable the disk writecache during boot up to make sure the data truly persistent (as in my previous storage company).

	▲	seebeen 3 days ago \| parent [-]
		So instead of saying "We removed fsync" you should say: "We redesigned the database write path to avoid paying the full fsync durability cost on every write"