I believe it is impossible to prevent dataloss if the device powers off during a write. The point about corruption still stands and appears to be used correctly from what I skimmed in the paper. Nice reference.
> I believe it is impossible to prevent dataloss if the device powers off during a write.
Most devices write sectors atomically, and so you can build a system on top of that that does not lose committed data. (Of course if the device powers off during a write then you can lose the uncommitted data you were trying to write, but the point is you don't ever have corruption, you get either the data that was there before the write attempt or the data that is there after).
Only way I know of is if you have e.g. a RAID controller with a battery-backed write cache. Even that may not be 100% reliable but it's the closest I know of. Of course that's not a software solution at all.
That's uh, not running out of power in the middle of the write. That's having extra special backup power to finish the write. If your battery dies mid cache-write-out, you're still screwed.
Most devices write sectors atomically, and so you can build a system on top of that that does not lose committed data. (Of course if the device powers off during a write then you can lose the uncommitted data you were trying to write, but the point is you don't ever have corruption, you get either the data that was there before the write attempt or the data that is there after).