On Fri, Feb 05, 2016 at 04:11:17PM -0500, Alan Stern wrote:
> On Fri, 5 Feb 2016, Marc MERLIN wrote:
>
> > The thing is async isn't great either.
> > I hate to say, but windows does this right, linux does not as far as I
> > can tell.
> > 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.
I agree. The nice thing though is that I think they do intermediate
syncs, so you get a progress bar that looks like everything is ok.
It's quite seemless to the user, hence my dream of having selective
syncs going through (one out of 100 or 1000) and the other ones being
skipped, to give that illusion of normal copy without slowing down the
speed and being done when the tool is done.
But I can see how on linux this would take extra cooperation between
userland and the underlying kernel code, just to do this, and likely
hasn't been deemed worth it.
Cheers,
Marc
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/ | PGP 1024R/763BE901
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