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Also this is the annual reminder that last time anyone did a survey on how good filesystems are at reporting up write errors, ZFS only qualified on reporting some errors and only common ones. Btrfs and ext4 both mostly swallowed write errors.

Part of that is infra, in the modern async "issue write and OK it to the process before the device OKs it" world, the FS can't reliable report such things.

That's where we got the postgresql "Fsync considered unreliable" from, a bug that persists on linux and can cause data loss on any DB setting other than "Fsync every write or do O_DIRECT"