using backup with 1/4 inch tape media

[Tom Merrick]

I found a couple of unexplained things while using backup at the 3002 level
and 1/4" low density cartridges (rmt0.4 and rmt0.5).

First, I wrote a tape label using dd, forward spaced over it, then did a
backup to the cartridge.  I got a write error stating that I had defective
media.

Second, I did several backups to the same tape cartridge (w/o a tape label).
Everything finished correctly, so I did a tcopy on the tape and found out that
my 60 MB cartridge had almost 112 MB on it!

Is backup ignoring the hardware and always writing high density?  This would
explain both problems above.

Tom Merrick
Ohio State University