[wellylug] unmounting versus stopping usb storage

[Daniel Pittman]

Jethro Carr <jethro.carr at jethrocarr.com> writes:
> On Mon, 2007-01-22 at 17:00 +0800, Bill Christiansen wrote:
>
>> I have a cellphone with a Kingston 512MB microSD card. It works fine
>> as a usb storage device under linux and I always unmount the drive
>> before unplugging the usb cable but the phone still complains that it
>> was not "stopped" before disconnecting and that the memory card may
>> be damaged. I'm assuming it's just missing a signal from Windows
>> telling it, it was stopped and that no real harm can come as it was
>> properly unmounted...?
>
> Providing you are unmounting the device correctly, and give it time to
> synchronise the cache before unplugging, there is no reason why this
> should cause data loss - as you said, it's possibly a special feature
> in the windows driver that's not implemented under Linux.

Actually, at least on the command line you can achieve the needed
disconnect -- with the small number of devices I tried it with:

  ] eject sda

That will also unmount the device if necessary; it works by sending the
SCSI messages to the device to cleanly disconnect it.

I can't assure you the phone will respect that but it /should/ work.
At the very least it shouldn't cause any harm, though a backup or a
scratch monkey is a good idea. :)

Regards,
        Daniel
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