Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752465Ab0LYV2l (ORCPT ); Sat, 25 Dec 2010 16:28:41 -0500 Received: from isrv.corpit.ru ([86.62.121.231]:41861 "EHLO isrv.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412Ab0LYV2k (ORCPT ); Sat, 25 Dec 2010 16:28:40 -0500 Message-ID: <4D166205.4070205@msgid.tls.msk.ru> Date: Sun, 26 Dec 2010 00:28:37 +0300 From: Michael Tokarev Organization: Telecom Service, JSC User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.1.15) Gecko/20101030 Icedove/3.0.10 MIME-Version: 1.0 To: Jaap Crezee CC: linux-kernel@vger.kernel.org Subject: Re: Slow disks. References: <20101220141553.GA6088@bitwizard.nl> <20101220190630.66084e1d@neptune.home> <20101222104306.GB30941@bitwizard.nl> <4D14BB36.1030304@msgid.tls.msk.ru> <20101225121407.GA2116@bitwizard.nl> <4D1633F2.3040109@jcz.nl> In-Reply-To: <4D1633F2.3040109@jcz.nl> X-Enigmail-Version: 1.0.1 OpenPGP: id=804465C5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1336 Lines: 31 25.12.2010 21:12, Jaap Crezee wrote: > On 12/25/10 13:19, Mikael Abrahamsson wrote: >> On Sat, 25 Dec 2010, Rogier Wolff wrote: >> Read errors will use parity drive and be re-written by the md layer. > > Can you show us *that* code? I don't recall seeing this behaviour.... > Just one read error and "bang". Or does the kernel not report the first > few read errors and just continues without telling us? > I don't like that. With a normal disk without raid I would have had some > log telling me the disk got bad? The code is in the md driver. This behavour is here for several years. If the drive respond in time ofcourse - if it tries to re-read the problematic sector forever and ignores other commands during this time it will be kicked off any array - be it software or hardware. The logs will be in whatever logfile your kernel messages are logged to. And yes, the application which reads the "problematic" area is _not_ notfied, since the data gets restored from other driver - if that was an md array with sufficient redundancy (any non-degraded raid other than raid0). /mjt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/