SUMMARY: How to force 8mm to write hi-density? (On used tapes)

From: Kevin Weinrich (
Date: Wed Aug 24 1994 - 13:36:41 CDT

I've got lots of answers so far, probably most of them correct.
This a "Probable Summary" because I'm in the process of testing it out.
If it works as advertised, I won't follow this message up.

According to the experts, if you're running 4.1.3 (maybe 4.1.2?) or
more recent, you just have to write to the appropriate device:
/dev/nrst0 for low density, /dev/nrst8 for high density,
/dev/nrst16 for low density with compression and /dev/nrst24 for
high density with compression.

Since I am using 4.1.3 (sorry I forgot to mention that) that
should give me what I need. Hopefully, the reason I was only
getting 2.3G was *not* because of what was on the tape, but
because I ignorantly used rst0 instead of rst24. Note: You
have to make sure your kernel is properly configured for one
of these high-capacity tape drives. Mine was, thanks to
the instructions that came with the drive. I just wish they
had also told me to use rst24. :-)

On the issue of erasing the tape, lots of folks suggested:
  mt -f /dev/rst24 erase
which is uninterruptible, and will take 3-4 hours.

Others suggested using a stereo speaker magnet, refrigerator
magnets (;-), or a magnetron from an old microwave oven.

Thanks loads for all the help!


This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:09:08 CDT