Path: utzoo!attcan!uunet!snorkelwacker!usc!cs.utexas.edu!rice!sun-spots-request
From: toense@cplxsys.ncsl.nist.gov (Robert E. Toense)
Newsgroups: comp.sys.sun
Subject: Re: Exabyte and file positioning...
Keywords: Hardware
Message-ID: <8622@brazos.Rice.edu>
Date: 6 Jun 90 18:54:17 GMT
Sender: root@rice.edu
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Refs:  Original: v9n197, Related: v9n141
X-Sun-Spots-Digest: Volume 9, Issue 202, message 2

There are three possible conditions for writing files on an Exabyte drive:

1) Beginning of tape,
2) Immediately following a write (no intervening motion), and
3) Immediately following writing a filemark (no intervening motion).

One of these conditions must exist or the write will fail.  In the
scenario described,

tar xf /dev/nrst0
mt -f /dev/nrst0 rew
mt -f /dev/nrst0 fsf 1
dump 4dsbf 54000 6000 100 /dev/nrst0 /dev/...

the dump does not follow one of the three conditions.  Exabyte drives DO
NOT work like 1/4" and 1/2" drives with regard to tape positioning and
writing.  Check the Exabyte manual for further discussion.

Robert E. Toense
(toense@cplxsys.ncsl.nist.gov)