From owner-freebsd-scsi@FreeBSD.ORG  Fri May 15 21:07:13 2015
Return-Path: <owner-freebsd-scsi@FreeBSD.ORG>
Delivered-To: freebsd-scsi@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 45C047CC
 for <freebsd-scsi@FreeBSD.org>; Fri, 15 May 2015 21:07:13 +0000 (UTC)
Received: from gw.catspoiler.org (unknown [IPv6:2001:4978:f:678::2])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id ED4581380
 for <freebsd-scsi@FreeBSD.org>; Fri, 15 May 2015 21:07:12 +0000 (UTC)
Received: from FreeBSD.org (mousie.catspoiler.org [192.168.101.2])
 by gw.catspoiler.org (8.13.3/8.13.3) with ESMTP id t4FL73nP021839;
 Fri, 15 May 2015 14:07:07 -0700 (PDT)
 (envelope-from truckman@FreeBSD.org)
Message-Id: <201505152107.t4FL73nP021839@gw.catspoiler.org>
Date: Fri, 15 May 2015 14:07:02 -0700 (PDT)
From: Don Lewis <truckman@FreeBSD.org>
Subject: Re: Dud tapes
To: dan@langille.org
cc: freebsd-scsi@FreeBSD.org
In-Reply-To: <B1544727-7A4F-49B4-B764-4A8D4E7FBFAD@langille.org>
MIME-Version: 1.0
Content-Type: TEXT/plain; charset=us-ascii
X-BeenThere: freebsd-scsi@freebsd.org
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: SCSI subsystem <freebsd-scsi.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/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: Fri, 15 May 2015 21:07:13 -0000

On 12 May, Dan Langille wrote:

> The problem occurred today on another tape after writing just 313 MB:
> 
> May 12 08:28:21 knew kernel: (sa0:sym0:0:1:0): WRITE FILEMARKS(6). CDB: 10 00 00 00 01 00
> May 12 08:28:21 knew kernel: (sa0:sym0:0:1:0): CAM status: SCSI Status Error
> May 12 08:28:21 knew kernel: (sa0:sym0:0:1:0): SCSI status: Check Condition
> May 12 08:28:21 knew kernel: (sa0:sym0:0:1:0): SCSI sense: MEDIUM ERROR asc:c,0 (Write error)
> May 12 08:28:21 knew kernel: (sa0:sym0:0:1:0): Command Specific Info: 0x1228
> May 12 08:28:21 knew kernel: (sa0:sym0:0:1:0): Error 5, Retries exhausted
> May 12 08:28:22 knew kernel: (sa0:sym0:0:1:0): WRITE FILEMARKS(6). CDB: 10 00 00 00 02 00
> May 12 08:28:22 knew kernel: (sa0:sym0:0:1:0): CAM status: SCSI Status Error
> May 12 08:28:22 knew kernel: (sa0:sym0:0:1:0): SCSI status: Check Condition
> May 12 08:28:22 knew kernel: (sa0:sym0:0:1:0): SCSI sense: MEDIUM ERROR asc:c,0 (Write error)
> May 12 08:28:22 knew kernel: (sa0:sym0:0:1:0): Command Specific Info: 0x1228
> May 12 08:28:22 knew kernel: (sa0:sym0:0:1:0): Error 5, Retries exhausted
> 
> The tape before this took 111 GB, the tape after, took 791 MB (and then the backup completed).
> 
> What do these errors mean? Does it indicate a dead tape?

Bad tape, dirty or defective head, some sort of mechanical tape handling
problem that affects the tape tension or movement, or less likely some
other drive problem.  MEDIUM ERROR means that the drive couldn't write
the bits to the tape and read them back correctly.