Reading past EOT on Sun QIC tape drive

[Yukon Born]

In article <4235 at brazos.Rice.edu> you write:
|X-Sun-Spots-Digest: Volume 9, Issue 5, message 13 of 19
|
|Can anyone tell me if it's possible to read past an end-of-tape mark on a
|Sun QIC tape drive (i.e., an "st" tape drive)?  One of my users
|accidentally blew away a tape he'd written by writing an empty file at the
|beginning of the tape.  Just about all of his data is still there, but I
|can't convince the st driver to let me read past the EOT marker.  It looks
|to me like the driver is trying to be too smart for its own good - is
|there a variable or something in the kernel I can patch to make the driver
|a little stupider...?  :-)

I tried to find this out because I did the same thing with a really
critical tape.  I got suggestions from the net, none of which helped.  I'm
no guru, but it seems to me the tape drive itself (the hardware) won't
proceed past an EOT - whatever I tried gave me a hard error.  If you
convince the software to ignore errors, the hardware forever tries to read
the EOT, or something.

If you find out how, _please let me know the trick_.  I even cut the tape
in the end - didn't work.  Here I think it's because the QIC format
doesn't get sync'ed up properly.