tlz04 density

[Allan E Johannesen]

On 15 May 91 01:20:25 GMT,
melanie at director.beckman.uiuc.edu (Melanie Anderson) said:
melanie> Sender: usenet at ux1.cso.uiuc.edu (News)

melanie> what is the 'recording density' of a TLZ04? and length?
melanie> inquiring minds want to know.

With a simple test program, I found I could write 107,528 10240 byte
blocks to the dat before error.  It would write 39,792 32768 byte
blocks, if anyone cares (I have a different system which writes this
different 'dump' blocksize).

Anyway, using sd 12000 6520, I observed that the tape utilization is
"safe".  i.e. dump says "<some number> of 10240 byte blocks is <some
percent> of the tape", and <some number> is well under <some percent>
of 107,528 (of course, I imagine this number could change on different
test runs even on the same tape).  i.e. this is very conservative.

I haven't used it on any filesystems which would test the boundary, so
I haven't worked up a more accurate s/d setup; you can experiment
until you find that the s/d formula yields a closer block-to-percent
ratio.