From owner-freebsd-current@FreeBSD.ORG  Mon Jun  2 23:23:36 2003
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 5A7C437B401; Mon,  2 Jun 2003 23:23:36 -0700 (PDT)
Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id B698343F75; Mon,  2 Jun 2003 23:23:35 -0700 (PDT)
	(envelope-from dan@dan.emsphone.com)
Received: (from dan@localhost)
	by dan.emsphone.com (8.12.9/8.12.9) id h536NZCK036211;
	Tue, 3 Jun 2003 01:23:35 -0500 (CDT)
	(envelope-from dan)
Date: Tue, 3 Jun 2003 01:23:35 -0500
From: Dan Nelson <dnelson@allantgroup.com>
To: Andreas Klemm <andreas@freebsd.org>
Message-ID: <20030603062335.GA8702@dan.emsphone.com>
References: <20030603055718.GA4763@titan.klemm.apsfilter.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20030603055718.GA4763@titan.klemm.apsfilter.org>
X-OS: FreeBSD 5.1-BETA
X-message-flag: Outlook Error
User-Agent: Mutt/1.5.4i
cc: current@freebsd.org
Subject: Re: whats an UDMA ICRC error ?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 03 Jun 2003 06:23:36 -0000

In the last episode (Jun 03), Andreas Klemm said:
> Hi,
> 
> my console today shows the following error message from my disk:
> 
> ad2: UDMA ICRC error cmd=read fsbn 74689079 of 74689079-74689206 retrying
> ad2: UDMA ICRC error cmd=read fsbn 74689079 of 74689079-74689206 retrying
> 
> What exactly does an UDMA ICRC error mean ?
> I think this is simply a read error.
> AFAIK an IDE disk doesn't have spare sectors or am I wrong ?
> How severe is this error ? What do you think ??

An ICRC error is an error detected by the IDE controller.  It usually
means a cabling problem, as a disk error would be reported by the
drive, not the controller.  From the ATA spec:

  ICRC shall be set to one if an interface CRC error has occurred
  during an Ultra DMA data transfer.  The content of this bit is not
  applicable for Multiword DMA transfers.

There are other error bits that indicate uncorrectable media errors.

-- 
	Dan Nelson
	dnelson@allantgroup.com