From MSDN i understood that when you invoke WinApi CreateFile without FILE_FLAG_NO_BUFFERING then WriteFile writes data to a system cache. It does not directly write to the physical disk. The OS will write it to the physical disk later on.
I wonder what happens when MoveFile is invoked. Is it guaranteed that after the MoveFile invocation the file is actually moved on the physical disk or is only the system cache updated?
If you want a guarantee that the move has made it to disk, use MoveFileEx with the MOVEFILE_WRITE_THROUGHflag, which does exactly that. Do note that this is possibly a serious performance impairment (with usually little or not benefit).
MoveFile by itself does not specify how the file is moved. It might indeed move, or it might copy-and-delete, and it might or might not use the buffer cache.
It is reasonable to assume that it indeed works using the buffer cache, and that "move" really means "move" on the same physical disk.
There is usually not much of a reason not to use the buffer cache, as apart from the computer crashing mid-operation or the user pulling the cable on an external disk, this is a perfectly reliable thing. Both scenarios are very rare. But even if they occur, the desastrous consequences are usually very mild, and very tolerable unless you tried to move huge directories with tens of thousands of files (usually, nothing was moved at all, or depending on the mode of operation, you have one intact original file and a stale file at the destination).
