Dump parameters for Exabyte

[Patrick Goebel]

Last week a fellow netlander posted an example of dump parameters to
use with an Exabyte:

/etc/dump 0fubsd /dev/nrst1 50 6000 54000 /dev/rid000a
/etc/dump 5fubsd /dev/nrst1 50 6000 54000 /dev/rid000e
/etc/dump 5fubsd /dev/nrst1 50 6000 54000 /dev/rid000f
/etc/dump 5fubsd /dev/nrst1 50 6000 54000 /dev/rid000g
/etc/dump 5fubsd /dev/nrst1 50 6000 54000 /dev/rid000h
/etc/dump 5fubsd /dev/nrst1 50 6000 54000 /dev/rid001e


When I use these parameters, the dump program estimates that 136 Mb of
files will consume 0.13 tapes.  This translates into 1.05 Gb for an entire
tape instead of the advertised 2.3 Gb.

I'd greatly appreciate knowing the "correct" parameters so that proper
capacity estimates are displayed.  The density parameter (d) of 54000 is
straight out of the Exabyte manual.  However, I do not understand the
blocking parameter (b) of 50 and the size parameter (s) of 6000.  In
particular, a 112m Sony 8mm tape is only 367 feet long, not 6000 feet.
Also, I suspect there may be a track parameter (t) missing.

If anyone knows the answer, posting it to the net might be useful to
others as well.  Thanks!

patrick goebel--romeo at lindy.stanford.edu