creating SYNC option for all USB devices in hal 0.0.4-10

Martin Pitt martin at
Tue Oct 18 00:08:01 PDT 2005

Hi Saimum!

Saimun Cheng [2005-10-17 23:58 +0800]:
> the problem is the USB drive would flash during saving. Then it would stop
> flashing. Then it would flash again when sync-ing (i think) after a few
> seconds. How would the user know when to remove?

A good indicator is the time when the LED entirely goes off. However,
you have to eject the device instead of just unmounting. We do this by
default in Ubuntu, first because of this problem, and second, because
merely unmounting does not work well with e. g. iPods.

> Without doubting you, Is the speed really so significant between sync and
> async?

Yes, it is. Depending on the application you use, you'll see a factor
of about 10 to 100.

Another fact is that at least the current implementation of sync is
EVIL for flash devices. I got reports of destroyed flash chips because
earlier versions of Ubuntu mouted devices as sync by default. But this
dramatically increases the wearout of certain portions of the flash
memory (FAT tables and the like), which leads to a greatly reduced
lifetime. So don't do it if you want to keep your devices for a while.


Martin Pitt    
Ubuntu Developer
Debian Developer
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