[RndTbl] USB flash memory stick wipeout

[Trevor Cordes]

On 2015-02-18 Hartmut W Sager wrote:
> Hello all,
> 
> I have had a wipout of 3 Kingston DataTraveller 16 GB and one
> Duracell 32 GB USB flash memory sticks.  Not only is the data lost,
> they can't even be reformatted!  (The data loss is no calamity - it
> was a duplicate backup.)

This will sound weird, but the sticks may be / have been / still are
good.  Make sure you test the sticks (and the reformat) with a 2nd
machine / 2nd card reader / 2nd usb cable / 2nd usb hub and/or all of
the above.  Make sure the contacts on the card and the reader are
clean.

I recently had a new high-end sd card act weird and it was because of a
usb1 cable (accident) to a unpowered gimmick usb hub chained 2 hubs
deep that was corrupting signal intermittently, to a card reader with
a flaky usb jack.  The card behaved normally once I eliminated those
problems.

Now I first mount all camera sd cards -o ro and do a cp (NOT mv!!)
first, *then* remount rw and clean it out.  Wacky stuff during a mv can
permanently mess up your card data and result in lost pix.  Wacky stuff
during a -o ro cp shouldn't result in anything more than a chance to
retry later.

> The one misbehaviour I had thoughtlessly done:  For about 9 months
> long, these sticks were stored in an above-counter kitchen cabinet,
> on the bottom level, and that cabinet has an under-the-cabinet
> 24-inch fluorescent fixture (tube and ballast) for illuminating the
> countertop.  I switched it on and off a few times a day.  The USB

Hmm, I haven't heard of that.  I do believe they are not magnetic, and
that a magnetic field could not change the trapped electrons, but I
could be wrong.

The reason I suspect something like in my scenario is because it would
be very strange that *all* those cards would go bad at once.  There
would be slight differences in location, etc, that would cause
variation in your scenario.

You could test the theory by trying in your (unchanged) setup a
known-good card that was not in that location.

Report back to us when you figure it out...