david@crbtechnologies.com wrote:
>The only way to totally destroy them is to physically remove the tape from the cart. and cut it up, shred it, etc. When I worked for the Govt. we used to test ways to recover data from tapes that had been "fried" and it was not fool-proof.
>
>Dave
>
>
>
>>No need to get high-tech, park 'em next to a large magnet for a few seconds.
>>
>>Ed.
>>
>>Ben Ostrowsky wrote:
>>
>>
>>
>>>I've got several dozen DDS tapes that I'd like to throw out. Before I
>>>do that, however, I'd like to make it non-trivial to read the data
>>>currently on them.
>>>
>>>I can't seem to figure out bcwipe; it works on files and block devices.
>>>I'm not sure what a block device is, but dmesg says "Attached scsi tape
>>>st0 at scsi1, channel 0, id 6, lun 0".
>>>
>>>[root@snoopy /tmp]# bcwipe -v -b /dev/st0
>>>Wipe /dev/st0 (y/[n]/a)?y
>>>Wiping device /dev/st0
>>>Writing to /dev/st0: Input/output error
>>>
>>>Perhaps it's not a block device:
>>>
>>>crw-rw---- 1 root disk 9, 0 Mar 23 2001 /dev/st0
>>>
>>>Any ideas how I can wipe these tapes? I don't have easy access to an
>>>MRI or a mile of copper wire, and I'd rather not trust the demagnetizer
>>>at the library -- it's not designed for this.
>>>
>>>I've been told that writing from /dev/urandom until the tape fills up
>>>would do the trick, but I don't even know how to do that!
>>>
>>>Haaaaalp!
>>>
>>>Ben
>>>
>>>
>>>
>>>
>>>
>
>-------------------
>
>
>
>
True, however Radio Shack used to sell an electromagnetic coil that
would do this(plugged in a circuit, drew a couple amps, and once fried a
CMOS that was 5 inches from it) that they called a bulk tape eraser, and
a big subwoofer magnet with the speaker on for ten minutes with the
cartrdige adhered to it followed by running the tape itself through a
shredder should ensure that anyone wanting data would have to derive 99%
of it. I had a friend who brought in a subwoofer magnet from a holed
subwoofer, and it, with no current going through it, totally scrambled a
monitor 7 inches from it. We had to degauss the monitor 8 cycles before
it returned to normal. In essence, feed end of tape into shredere, then
turn shredder on and let it unspool the tape, after frying. Or do what a
senior cop did with police department data on a failed HD-- took it to a
range, shot it with a 9 mm personal weapon 6 times, then threw it in the
city incinerator and supervised the lighting and operation of same for
10 minutes. Melting works good, so pull the tape out, set in an ashtray,
light and burn-- lighter fluid or lamp oil bathing will denature the
coating also, as will an acid bath in drain opener of the commercial
sort for 1\2 hour. NOT kidding!!
John.
-- _______________________________________________________________________________ Registered Linux User #276212, Machine #158988 "Use what works best for your needs, at minimum total cost of ownership."
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