[sitkack]

Fsync should always be on by default. Require the user to turn it off. I'd even argue that `fsync` itself is broken and that semantics should be inverted.

[eternalban]

What about pervasive virtualization? The issue here is not really fsync. A fault-tolerant in-memory cluster should not lose data.

[sitkack]

Writes should be durable by whatever means the platform deems durable. Durable should be the default. It should take work to have non-durable io.