From owner-freebsd-scsi@FreeBSD.ORG  Mon Aug 11 10:49:50 2003
Return-Path: <owner-freebsd-scsi@FreeBSD.ORG>
Delivered-To: freebsd-scsi@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id A603B37B401; Mon, 11 Aug 2003 10:49:50 -0700 (PDT)
Received: from mail.sandvine.com (sandvine.com [199.243.201.138])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id C8CFD43FAF; Mon, 11 Aug 2003 10:49:49 -0700 (PDT)
	(envelope-from don@sandvine.com)
Received: by mail.sandvine.com with Internet Mail Service (5.5.2653.19)
	id <305LHV30>; Mon, 11 Aug 2003 13:49:48 -0400
Message-ID: <FE045D4D9F7AED4CBFF1B3B813C853370274221F@mail.sandvine.com>
From: Don Bowman <don@sandvine.com>
To: "'Kenneth D. Merry'" <ken@kdm.org>, Don Bowman <don@sandvine.com>
Date: Mon, 11 Aug 2003 13:49:46 -0400
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2653.19)
Content-Type: text/plain;
	charset="iso-8859-1"
cc: "'freebsd-scsi@freebsd.org'" <freebsd-scsi@freebsd.org>
cc: "'aic7xxx@freebsd.org'" <aic7xxx@freebsd.org>
Subject: RE: Ongoing U320 AIC7902 Seagate ST318453LW issues, SCB timed out
X-BeenThere: freebsd-scsi@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: SCSI subsystem <freebsd-scsi.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-scsi>,
	<mailto:freebsd-scsi-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-scsi>
List-Post: <mailto:freebsd-scsi@freebsd.org>
List-Help: <mailto:freebsd-scsi-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-scsi>,
	<mailto:freebsd-scsi-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 11 Aug 2003 17:49:51 -0000

> From: Kenneth D. Merry [mailto:ken@kdm.org]
> 
> On Fri, Aug 08, 2003 at 13:43:55 -0400, Don Bowman wrote:
> > Just to confirm i'm talking about the same thing...
> > my seagate device reports 255 tagged openings:
> > 
> > # camcontrol tags 0:0:0
> > (pass0:ahd0:0:0:0): device openings: 255
> > 
> > but seagate indicates the device has only support for
> > 64. Am i reading something different here?
> 
> You'll see 255 openings until we get a queue full response 
> from the drive.
> Then it'll go down to however many transactions we had 
> outstanding when the
> queue full happened.
> 
> If you want a little more information (e.g. how many transactions are
> outstanding at a given moment), try:
> 
> camcontrol tags da0 -v
> 
> Ken

So i've reconfirmed, the drive supports a max of 64 tags.
under load I see the max go down to 252, how can that make
sense? under severe load it may go lower, to e.g. 33.

???