Here is a post from him: https://lore.kernel.org/linux-btrfs/20190623204523.GC11831@hungrycats.org/T/ https://lore.kernel.org/linux-btrfs/20190623204523.GC11831

Here is a post from him: https://lore.kernel.org/linux-btrfs/20190623204523.GC11831@hungrycats.org/T/ https://lore.kernel.org/linux-btrfs/20190623204523.GC11831@h... TLDR: Very few drives don't implement flush correctly. Notice that he mainly uses hard disks, not SSDs/NVMe. Failure often occurs when two (usually rare) things occur at once. E.g. remapping an unreadable sector while power-cycling.