On Thu, Dec 03, 2009 at 10:25:23PM +0330, Roozbeh Gholizadeh wrote: > On Thu, 03 Dec 2009 21:04:03 +0330, Greg KH <greg@xxxxxxxxx> wrote: > > > On Thu, Dec 03, 2009 at 08:43:11PM +0330, Roozbeh Gholizadeh wrote: > >> On Thu, 03 Dec 2009 03:09:45 +0330, Greg KH <greg@xxxxxxxxx> wrote: > >> > >> > On Thu, Dec 03, 2009 at 01:52:36AM +0330, Roozbeh Gholiza wrote: > >> >> > >> >> I've recently have this issue that moving files takes a lots of > >> time, at > >> >> first it starts with decent speed (3MB/S) then it gradually decreses > >> >> into > >> >> 100/200KB/S. My usb flashdisk is 4gb formatted in fat32. > >> >> It seems to me it is related to kernel.Anyway here is my info : > >> > > >> > Do you have the "sync" option for fat32 enabled? If so, that will > >> cause > >> > this to happen. Several distros enabled this a while ago to ensure > >> you > >> > would get the data written out quicker. > >> > > >> > >> I guess it is turned off.At least i turned it off with every solution > >> posted in internet, such as creating mount policy, unmounting and > >> remounting with mount async option, also used 3 different versions of > >> kernel and all seems to suffer from this. > >> > >> Besides, enabling sync option and having slow performance, couldnt this > >> also considered as a bug? > > > > Not really, your device could just be slow. Are you sure it isn't a > > device issue? > > > > Try doing this on a USB disk drive, with rotating media behind it, that > > would take the USB connection out of the loop. > > > > Yes. I am pretty sure it isnt my device issue or usb port issue. > 2 reasons : > 1.it works nice with windows and even in dos! What are the speeds you are getting overall with both Windows and DOS? > 2.at first the speed is really high, around 10mb/s but gradually speed > decreases. and also when you stop the transfer, device keeps working for > about 10-15 sec. That is normal, it is the io flushing out to the device afterward. In the beginning, the vfs caches a lot of it (hence really quick response) and then it starts to flush stuff out to the disk itself. > but normally if you stop the trasfer, my usb device led > turns off. > I also checked this issue with 3 other usb flashdisk from 3 different > brands. So the same thing happens on all of them? Again, that's normal here. Unless you can say that this is a regression from a previous kernel version, I'd say this is just the way things work on Linux. thanks, greg k-h -- 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
