From owner-freebsd-scsi  Wed Apr 28  8:55:30 1999
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Date: Wed, 28 Apr 1999 16:52:10 +0100
Subject: Re: QIC tape problems on -stable (was: hanging `tar xfvR /dev
	/nrst0' process, can i debug it?)
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>
>These are *amazingly* broken drives then. The SCSI specification says that
>a write of *zero* filemarks is to flush any pending writes. You have to do
>this when you do a read hardware position in order to avoid an ambiguity
>in the spec as to the true position as affected by data in the tape drive
>buffer.

Doesn't Read Position (34h) give all the info you need, i.e. Physical pos.,
logical pos. and number of blocks in buffer?  I agree that flushing is
safer, but surely one could avoid it if necessary.

Andrew.





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