Solved Re: [Dirvish] slow writing to external USB2 hard disc

[Eric Mountain]

On Monday 14 May 2007, Gert Brinkmann spake thus:
> 1) udev (or which layer ever) should mount drives with async,commit=1 as
> default instead of using the extremely slow sync mode.

Per your mail you are using Debian unstable.  I am using the same distrib, but 
my USB memory cards are getting mounted async.

What package are you using to do the USB device mounting?  usbmount or the 
HAL+pmount combination (I'm using the latter - pmount uses async by default).  
If you think the Debian setup is to blame then you should file a bug report.

> 2) I understand that sync is slower than async, but IMHO it is a bug,
> that it takes more than 20 times longer!?

What makes you think a factor of 20 is a bug?  What do you base your opinion 
on?  For one thing, the hardware is being treated completely differently and 
sync mode involves more work overall (this is especially true on FAT based 
disks, don't know about ext2 although I would imagine the block usage bitmaps 
would undergo some thrashing that would be avoided in async).  People on the 
linux-kernel and similar mailing lists would be bound to answer this far 
better though.

Maybe the following links can be of interest:

http://readlist.com/lists/vger.kernel.org/linux-kernel/22/111771.html
http://lkml.org/lkml/2005/5/16/60

Cheers,
Eric
-- 
Eric Mountain