From owner-freebsd-usb@FreeBSD.ORG  Mon Oct 26 00:27:50 2009
Return-Path: <owner-freebsd-usb@FreeBSD.ORG>
Delivered-To: usb@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 3023B106566C;
	Mon, 26 Oct 2009 00:27:50 +0000 (UTC)
	(envelope-from non@ever.sanda.gr.jp)
Received: from smtp10.dti.ne.jp (smtp10.dti.ne.jp [202.216.231.185])
	by mx1.freebsd.org (Postfix) with ESMTP id BC80A8FC16;
	Mon, 26 Oct 2009 00:27:49 +0000 (UTC)
Received: from [127.0.0.1] (n166h120.dhcp.kanazawa-it.ac.jp [202.13.166.120])
	by smtp10.dti.ne.jp (3.11s) with ESMTP AUTH id n9Q055kG009702;
	Mon, 26 Oct 2009 09:05:09 +0900 (JST)
Message-ID: <4AE4E7AF.8060103@ever.sanda.gr.jp>
Date: Mon, 26 Oct 2009 09:05:03 +0900
From: non@ever.sanda.gr.jp
User-Agent: Thunderbird 2.0.0.23 (Windows/20090812)
MIME-Version: 1.0
To: "M. Warner Losh" <imp@bsdimp.com>
References: <20091025.133437.-1844000782.imp@bsdimp.com>
In-Reply-To: <20091025.133437.-1844000782.imp@bsdimp.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Mailman-Approved-At: Mon, 26 Oct 2009 01:04:28 +0000
Cc: usb@freebsd.org, hackers@freebsd.org
Subject: Re: Help troubleshooting...
X-BeenThere: freebsd-usb@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: FreeBSD support for USB <freebsd-usb.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-usb>
List-Post: <mailto:freebsd-usb@freebsd.org>
List-Help: <mailto:freebsd-usb-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 26 Oct 2009 00:27:50 -0000

M. Warner Losh wrote:
> I have a usb stick (8GB) on it.  This stick has about 5GB of junk on
> it at this point.
> 
> I tried to do 'cat * > /dev/null' recently, to measure how fast it
> goes.  It got about 1GB into the drive and then I got device missing
> messages.
		:
> So devfs thinks the device went missing:

Warner-san, maybe it is caused by the hardware problem on the USB flash 
memory. Some chip on the memory might have too much heat when you access 
the memory at fast rate. Then it stops working.

// Noriaki Mitsunaga