Re: Is there a way to limit VFAT allocation?

From: Grzegorz Kulewski
Date: Mon Oct 16 2006 - 06:38:14 EST


Hi,

On Mon, 16 Oct 2006, Zoltan Boszormenyi wrote:
I have bought a 2GB MP3 player / flash disk
that erroneously partitions and formats its storage.
The built-in firmware has an off-by-one bug that
creates the partition one cylinder larger that the
disk size allows and then it formats the VFAT fs
according to the buggy partition size. No wonder
when I try to copy large amounts of data to the
flash disk it detects errors and then remounts it
read-only.

I tried to repartition and reformat it three times
with different mformat or mkdosfs options
but as soon as I remove it from the USB port,
the device detects changed disk format and
automatically reformats itself again, so it
stays buggy.
[snip]
Unfortunately, the firmware is not upgradeable.
The device in question is a Telstar UFM-102B.

Is there a way to tell the VFAT driver to exclude
the last N sectors from the allocation strategy?

Maybe try to setup device mapper linear mapping backed by portion of that partition that is ok (== one cylinder smaller) instead of messing with filesystem drivers. And then create filesystem on top of that new device.


Grzegorz Kulewski

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