On Sat, 30 Mar 2019 at 13:09, Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote: > > If controller is doing so, it must have its own power or at least finish > flush when controller writes to its fast cache. > The controller has its own battery backup to power the DRAM cache, as well as flash storage to dump it onto in the exceedingly unlikely event that the battery gets depleted. > For cache case, if we have enough data, we could still find some clue on > the flush execution time. > > Despite that, for that enterprise level usage, it's OK. > > But for consumer level storage, I'm not sure, especially for HDDs, and > maybe NVMe devices. > How do you distinguish who is a who? Am I an enterprise or a consumer? Regards