Re: buffers not syncing correctly during shutdown

2009/10/14 Mario Lobo <mlobo_at_digiart.art.br>

> > "Mario Lobo" <mlobo_at_digiart.art.br> writes:
> >> I must add that even windows has a "Safely Remove Hardware" before
> >> unplugging the usb device.
> >
> > What it really means is "sync the filesystem and tell me if there are
> > any open or locked files".  In most cases, you can yank the USB stick
> > out without adverse consequences.
> >
> > DES
> > --
> > Dag-Erling Sm繪rgrav - des_at_des.no
> >
> That IS true ! but like you said, "most cases" <> "all cases". Once, on a
> company I was doing work at, I clicked on "Safely Remove Hardware" and it
> said "can愒 do it. device busy", although there was (apparently) nothing
> using any files from the stick. I yanked it out anyway. result: the 3
> files I edited from the stick were gone :(. Since I don愒 know when I am
> gonna hit a case that doesn愒 belong to "most", I always try to remember
> to unmount (i.e. Safely Remove Hardware) the stick before unplugging it.
>
> How Windows deals with USB removable storage depends on how you configure
the storage policy for the individual device, and globally for all removable
storage devices.

The default in Windows XP is "Optimise for performance", which requires the
use of the "Safely remove hardware" feature.  This enables write caching on
the device, which can lead to data loss if you remove the device before data
is actually flushed/written.

You can change it to "Optimise for quick removal", which disables write
caching, so you can remove the device at pretty much any time.

It's all done via the Policies tab in the Device Properties, accessible via
the Device Manager or by right-clicking->Properties on the device in Windows
Explorer.

I believe the default was switched at some point, though, so that the Safely
Remove isn't always needed.
-- 
Freddie Cash
fjwcash_at_gmail.com