Looking to read past EOT on DDS/DLT/LTO

[Chuck Guzis]

On 01/25/2017 02:16 PM, Eric Smith wrote:
> On Jan 25, 2017 12:24 PM, "Stan Sieler" <sieler at allegro.com> wrote:
>> We have a friend with a "tape" (DDS, DLT, or LTO ... don't know
>> which yet) to which was written a system backup.  Thousands of
>> files, with an EOF between each file, and a double EOF + EOT at the
>> end.
>> 
>> The problem: They then accidentally overwrote the start of the tape
>> yesterday with about 1 KB of data, plus EOT.
> 
> I hope someone can prove me wrong, but I think that short of a major
> effort to hack the drive firmware, the data is gone. Modern tape
> drives are "too smart" to allow reading past logical EOT, and the
> tape format is too complex to allow fooling the firmware by any
> simple means.

With nothing left to lose, I suppose that one might overwrite the EOT
and then kill power during the write, then attempt to read backward from
the end of the tape.

I've never done it, but who knows?

--Chuck