From owner-freebsd-stable@FreeBSD.ORG Thu Jul 19 14:58:25 2007 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id E0C7F16A401; Thu, 19 Jul 2007 14:58:25 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 9F68A13C494; Thu, 19 Jul 2007 14:58:25 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.13.8/8.13.4) with ESMTP id l6JEtu5H085408; Thu, 19 Jul 2007 08:55:56 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Thu, 19 Jul 2007 08:56:02 -0600 (MDT) Message-Id: <20070719.085602.-1632631676.imp@bsdimp.com> To: koitsu@freebsd.org From: "M. Warner Losh" In-Reply-To: <20070718200937.GA15560@eos.sc1.parodius.com> References: <200707181942.45045.idiotbg@gmail.com> <469E61DB.4000402@pcbsd.com> <20070718200937.GA15560@eos.sc1.parodius.com> X-Mailer: Mew version 5.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0 (harmony.bsdimp.com [127.0.0.1]); Thu, 19 Jul 2007 08:55:56 -0600 (MDT) Cc: kris@pcbsd.com, freebsd-stable@freebsd.org Subject: Re: removing external usb hdd without unmounting causes reboot? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Jul 2007 14:58:26 -0000 In message: <20070718200937.GA15560@eos.sc1.parodius.com> Jeremy Chadwick writes: : This would alleviate concerns over data loss, would it not? No. The problem is more basic: the device *driver* is gone. All the code unwinding has happened. The physical device is also gone, which is what triggered the detach. Doing synchronous writes wouldn't help. The next time the file system was touched, it would dereference a device that no longer exists, giving random results, in this case a crash. Meaning no disrespect for enthusiastic users, I really wish that people with "suggestions" would actually try to fix it themselves before making such obviously wrong comments. I have the right to say this because I have tried to fix this, and have run into these issues. Like I've said before, if it were easy, one of the dozen or so people that have tried to fix it in the past 8 years would have succeeded. Warner