From owner-freebsd-bugs  Wed Feb  7 15:05:54 1996
Return-Path: owner-bugs
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.3/8.7.3) id PAA05420
          for bugs-outgoing; Wed, 7 Feb 1996 15:05:54 -0800 (PST)
Received: (from se@localhost)
          by freefall.freebsd.org (8.7.3/8.7.3) id PAA05407
          Wed, 7 Feb 1996 15:05:52 -0800 (PST)
Date: Wed, 7 Feb 1996 15:05:52 -0800 (PST)
From: Stefan Esser <se>
Message-Id: <199602072305.PAA05407@freefall.freebsd.org>
To: koeck@pluto.mpi-hd.mpg.de, se, freebsd-bugs
Subject: Re: kern/527
Sender: owner-bugs@FreeBSD.ORG
Precedence: bulk

Synopsis: dump causes assertion in ncr.c

State-Changed-From-To: open-analyzed
State-Changed-By: se
State-Changed-When: Wed Feb 7 14:58:00 PST 1996
State-Changed-Why: 
This appears to be caused by the generic SCSI code sending a 
START STOP UNIT command at each open of the raw disk device.
Two programs are known to possibly open such a device multiple
times within a fraction of a second: DUMP and FSCK.
The NCR driver sends these commands with ORDERED TAG messages,
which appears to confuse some IBM drives, if several are issued
concurrently.

This should be changed in the generic SCSI code, which easily
could count the number of times a device has been opened and
which should start the drive only once.