[arch-general] Finally found a solution to slow USB on HAL

[Philipp Überbacher]

Excerpts from Nilesh Govindarajan's message of 2010-06-29 05:27:42 +0200:
> On 06/29/2010 05:44 AM, Ross wrote:
> > On 29/06/10 08:52, Philipp Überbacher wrote:
> >> Excerpts from Denis A. Altoé Falqueto's message of 2010-06-28 18:33:30
> >> +0200:
> >>> On Mon, Jun 28, 2010 at 1:21 PM, Pálffy András Gergely
> >>> <pagesailor at gmail.com> wrote:
> >>>> Works here too. Great, thanks.
> >>>>
> >>>> On Mon, Jun 28, 2010 at 1:25 PM, Nilesh
> >>>> Govindarajan<lists at itech7.com>wrote:
> >>>>
> >>>>> I have made a patch for /usr/share/hal/fdi/20-storage-methods.fdi
> >>>>> to force
> >>>>> async file transfer for vfat filesystems by commenting out flush
> >>>>> and sync as
> >>>>> valid options from the list.
> >>>>> I checked the thing, now I'm getting the old high speed USB transfer.
> >>>>> Do take a look at it, and comment.
> >>>
> >>> Yes, but you should keep in mind that you'll spend extra time when you
> >>> want to unmount your USB stick. So I prefer a "slow" transfer and a
> >>> fast unmount, because usually I'm in hurry for taking off the USB
> >>> drive and the unmounting visualizations are not very smart (only in
> >>> KDE SC 4.4 it is really usable).
> >>
> >> Actually I was recently wondering a bit about the unmounting part,
> >> especially with USB sticks. I do have udev rules, taken from the wiki,
> >> in place that handle automatic mounting. There's also a unmounting part,
> >> which afair removes created dirs, but I guess this is only called after
> >> the usb drive is removed. It did happen more than once to me that a file
> >> transfer seemed to be complete, but when I just removed the drive, the
> >> data was gone. Is there a way to provide automatic safe removal? Manual
> >> unmounting is a bit of a PITA, as you need to have a terminal ready,
> >> guess sdN and type a line, where the device guessing part is the most
> >> problematic. I tend to use /dev/sdN to make sure that I remove the
> >> device from all mount points. Thanks for any advice.
> >
> > I am no expert and am probably missing something here, but it should be
> > simple to create a desktop icon and/or menu option to issue the sync
> > command. That way you could have the speed of asynchronous mount and
> > clicking the icon or menu option before removing the drive will write
> > any buffered data to the device to prevent data loss if removing the
> > device without umounting. As the sync command syncs all mounted drives
> > you don't need to provide the /dev/sdN.
> >
> > Ross.
> 
> Yeah exactly !
> After copy your data to the drive, run the sync command or setup a 
> keyboard shortcut for it :-)
> This will give you high speed transfer along with no data loss \m/
> 
> But if you're very forgetful to remove the drive without pressing the 
> keyboard shortcut for sync, then you're in trouble and this patch is not 
> for you.
> 
> Alternatively, you could write a bash daemon as per this tutorial: 
> http://j.mp/9DRWOF
> 
> which will check for a usb stick's existence and if its mounted, sync 
> every 15-30 seconds.

Heh, I didn't even know about the sync command and not about the
difference between sync/async either. Guess I'll have to check my mount
options and udev rules. The bash daemon tutorial thing looks handy and
simple enough too, so thanks!
-- 
Regards,
Philipp

--
"Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan