<jhein AT timing DOT com> writes:
> I've seen problematic behavior when the tape unit is set to have a
> particular block size (that may not match at read time what was used
> to write a tape).

That was the problem.  In my rc.local file I have:

/bin/mt defcompression 0
/bin/mt defblksize 0

But with the mt command broken (it now uses /dev/tape as the
default instead of /dev/nst0) I should have had:

/bin/mt -f /dev/nst0 defcompression 0
/bin/mt -f /dev/nst0 defblksize 0

Thanks to John Hein and everyone.

Steve
-- 
Steven J. Backus                        Computer Specialist
University of Utah                      E-Mail:  steven.backus AT utah DOT edu
Genetic Epidemiology                    Alternate:  backus AT math.utah DOT edu
391 Chipeta Way -- Suite D              Office:  801.587.9308
Salt Lake City, UT 84108-1266           http://www.math.utah.edu/~backus