On Fri, 2016-02-05 at 16:11 -0500, Alan Stern wrote: > On Fri, 5 Feb 2016, Marc MERLIN wrote: > > When a windows copy is finished, it's pretty much on flash (maybe with a > > second delay) > > On linux, it is if I accept a speed that 50x slower, or it's not and > > data is lost if I pull my usb device after the copy is over without > > unmount (I have automatic mount). > > In other words, with linux, the copy either finishes way before it's on > > flash, or takes many times longer. > > This is more of a user interface issue than anything else. In Windows > the copy command waits until the data has been transfered to the disk, > whereas in Linux the cp command doesn't wait (more correctly, it waits > for the operating system to accept the data but no longer). If you do > want to wait, you could write a little script or shell alias that does > the cp command followed by a sync. > > In theory, the copy command in Windows shouldn't need to wait either. > But then you'd run into trouble if you unplugged the USB device without > first clicking on the "Safely remove hardware" button -- which > essentially does a sync. Well, not fully. Linux knows two modes. Full caching and totally synchronous operations. It seems to me we could do better. Like starting the write as soon as dirty blocks appear and do an fsync upon close. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
