OK
- boundary case when WRITING to NTL tested (NTL-X136)
    tar --block-size=64 -cvf - /usr/bin /usr/users /usr/lib | /usr/local/bin/multivol --medium-changer-script=/usr/local/bin/medium_changer.sh --output-file=/dev/st0 --block-size=32768
NOT YET OK- boundary case when READING from NTL (NTL-X136) tested, including
  data integrity (--compare with tar), provided you eject the tape
  first (mt -f /dev/st0 offline) so the right one can be loaded.
    /usr/local/bin/multivol --medium-changer-script=/usr/local/bin/medium_changer.sh --input-file=/dev/st0 --block-size=32768 | tar --compare --block-size=64 -vf - 
- for OL8 (not NTL), you need to put the tape-init and tape-deinit scripts
  as shown in examples but not in ./test.sh

BUGS
   - code is very badly written
   - no error checking on scripts.

[ untested yet: no small tape ]


