From owner-freebsd-questions@freebsd.org Mon Oct 17 17:45:37 2016 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 94C33C150C0 for ; Mon, 17 Oct 2016 17:45:37 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mx02.qsc.de (mx02.qsc.de [213.148.130.14]) (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 5D88C381 for ; Mon, 17 Oct 2016 17:45:36 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from r56.edvax.de (port-92-195-117-205.dynamic.qsc.de [92.195.117.205]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx02.qsc.de (Postfix) with ESMTPS id BFAF8276CF; Mon, 17 Oct 2016 19:45:27 +0200 (CEST) Received: from r56.edvax.de (localhost [127.0.0.1]) by r56.edvax.de (8.14.5/8.14.5) with SMTP id u9HHjRrh004487; Mon, 17 Oct 2016 19:45:27 +0200 (CEST) (envelope-from freebsd@edvax.de) Date: Mon, 17 Oct 2016 19:45:27 +0200 From: Polytropon To: "Jason C. Wells" Cc: freebsd-questions@freebsd.org Subject: Re: Drive Read Errors Message-Id: <20161017194527.c56ab9a1.freebsd@edvax.de> In-Reply-To: <7353bec4-4a98-7e86-bda9-4c401bb2ad71@fastmail.com> References: <7353bec4-4a98-7e86-bda9-4c401bb2ad71@fastmail.com> Reply-To: Polytropon Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Oct 2016 17:45:37 -0000 On Mon, 17 Oct 2016 10:02:28 -0700, Jason C. Wells wrote: > I have a drive that has always been troublesome. My first indication was > that the gmirror would end up degraded and restoring it would be > extremely time consuming. (Excuse the terminology, it has been a while > since I did that part.) I gave up on the drive and removed it from the > mirror permanently. Good decision. > I recently used smartmontools long test and discovered that the drive > had read errors. > > In your experience, is there any value in trying to use drive by mapping > bad sectors or partitioning around the errors? When those errors start "bubbling up" and become visible to the OS, it's usually too late. The drive can re-map defective sectors internally. When it runs out of "spare sectors", the errors are being processed by the operating system's driver for direct access storage devices. Those errors usually indicate that the drive has reached the end of its (useful) life. The result: When you mark bad sectors (see "man badsect" for details), you will usually get more and more errors, so you just will see more problems of the same kind in the future. The drive already is broken. It's not that _modern_ drives can be "partitioned smaller" and then continue to work properly for decades. ;-) Of course there is no problem continuing to use the disk for some non-critical data, like a scratch disk ("fragile storage"), but the problems you can expect probably reduce the usefulness significantly. -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...