Sun tape drive question

[Vidiot]

OK, bear (or bare:-) with me on this question.  First some details.

I have a Sun 3/60 with a SCSI tape drive, for writing QIC-11 and QIC-24
tapes.  While doing dumps, I set the footage size for thge OS3.5 dump to
"feet * 9 * .9", the magical formula used for the s option.  Everything
works just fine.

On the 4/110 that we just brought in, the Sun OS4.1 dump is different, in
that real footage numbers are used, not the calculated stuff of 3.5.  So,
I tell dump to use 600 feet, but dump fails and gives a write error at
footage 4946.  Wait-a-minute, using the old formula that is 610 feet.  I
am using the DEI 5 FIFTY 5 cartridges, which works ok when using a value
of 5100, under OS3.5.

The dump will only work when I use a value of 500 for the footage.  525
fails.  Does anyone know what is really going on in the 4.1 dump?  What is
a QIC-24 tape really supposed to hold?  It estimated a dump of 104.54MB,
which should not spill into a third tape, but it does.  At 60MB a tape,
the dump should have fit onto two tapes.  Am I way off base here?

Please e-mail responses.

Thanks in advance.

Mike Brown

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