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!
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. 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.
Unfortunatly i do not have access to usb hard disk right now, but i will
test that too and see the results.
But if i know correct, the reason begind sync option is just write
everything at that moment. so why stopying the trasfer keeps device busy
for more than 20sec, it sounds more async than sync to me.
thanks
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