From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87390C433E2 for ; Wed, 2 Sep 2020 14:51:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 560CF2078E for ; Wed, 2 Sep 2020 14:51:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=karlsbakk.net header.i=@karlsbakk.net header.b="XHIJWQ7n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726536AbgIBOvu (ORCPT ); Wed, 2 Sep 2020 10:51:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727800AbgIBOul (ORCPT ); Wed, 2 Sep 2020 10:50:41 -0400 Received: from zimbra.karlsbakk.net (zimbra.karlsbakk.net [IPv6:2a0a:51c0:0:1f:4ca5::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04C72C061244 for ; Wed, 2 Sep 2020 07:50:40 -0700 (PDT) Received: from localhost (localhost.localdomain [IPv6:::1]) by zimbra.karlsbakk.net (Postfix) with ESMTP id 2919A3C273F; Wed, 2 Sep 2020 16:50:39 +0200 (CEST) Received: from zimbra.karlsbakk.net ([IPv6:::1]) by localhost (zimbra.karlsbakk.net [IPv6:::1]) (amavisd-new, port 10032) with ESMTP id jv6Gj56WRldB; Wed, 2 Sep 2020 16:50:37 +0200 (CEST) Received: from localhost (localhost.localdomain [IPv6:::1]) by zimbra.karlsbakk.net (Postfix) with ESMTP id CC9433C27C6; Wed, 2 Sep 2020 16:50:37 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.10.3 zimbra.karlsbakk.net CC9433C27C6 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=karlsbakk.net; s=1DC131FE-D37A-11E7-BD32-3AD4DFE620DF; t=1599058237; bh=zKMm47a+lH4Sa+Lk9BrLkLJIrdtV8hT//g9f4c0Pdxg=; h=Date:From:To:Message-ID:MIME-Version; b=XHIJWQ7nNUMpPTLMlcaisvEoz25wYeiwvcTDMDNeXT29M4BFlHD8t9/n8xm9aGQ1F 0SkKRCKn95vO8dVxUjs2ttDODNseQH7xnsuq/dbQ911ZkOu7wFN4a4xS6KuH96a9fB ozlelm6MvrMUdcycl/1brMN2GQ9MHmKXq5DL8kL9gm/XbocuJLdgPE3EmmLyygwkaq kguRa9UQnj+8qU4MndyH/c6nvqtEpQ4Ka3DvbE4yQ4iXNQLlattRxzKCs0M4alDeLr iPgLqfrLHILTD0FqogBw8hAiuwFu74/Sdb37JVdmpnceyTa6nNgAvumvXQZ3reiB4u xVq9jEOVLFcKQ== X-Virus-Scanned: amavisd-new at zimbra.karlsbakk.net Received: from zimbra.karlsbakk.net ([IPv6:::1]) by localhost (zimbra.karlsbakk.net [IPv6:::1]) (amavisd-new, port 10026) with ESMTP id T4nl3ZJYxuMk; Wed, 2 Sep 2020 16:50:37 +0200 (CEST) Received: from zimbra.karlsbakk.net (localhost.localdomain [127.0.0.1]) by zimbra.karlsbakk.net (Postfix) with ESMTP id A9C343C273F; Wed, 2 Sep 2020 16:50:37 +0200 (CEST) Date: Wed, 2 Sep 2020 16:50:37 +0200 (CEST) From: Roy Sigurd Karlsbakk To: Adam Goryachev Cc: "David C. Rankin" , Linux Raid Message-ID: <1375662956.965590.1599058237477.JavaMail.zimbra@karlsbakk.net> In-Reply-To: <8dce17fb-13df-b273-cc3d-b3f71d180354@websitemanagers.com.au> References: <75076966.1748398.1597773608869.JavaMail.zimbra@karlsbakk.net> <001c5a42-93fd-eddb-ba86-aa3e2695f2a8@thehawken.org> <37b43194-f372-dd04-a319-34406f63c5a2@suddenlinkmail.com> <51057261.933837.1599053769942.JavaMail.zimbra@karlsbakk.net> <8dce17fb-13df-b273-cc3d-b3f71d180354@websitemanagers.com.au> Subject: Re: Feature request: Remove the badblocks list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [2a01:79c:cebf:61e4:95bb:fcf8:43db:53b] X-Mailer: Zimbra 8.8.10_GA_3801 (ZimbraWebClient - FF80 (Mac)/8.8.10_GA_3786) Thread-Topic: Feature request: Remove the badblocks list Thread-Index: eVOerR2xJ6KXm/tzhlDwjHWTpCGxWQ== Sender: linux-raid-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org > I'm no MD expert, but I there are a couple of things to consider... >=20 > 1) MD doesn't mark the sector as bad unless we try to write to it, AND > the drive replies to say it could not be written. So, in your case, the > drive is saying that it doesn't have any "spare" sectors left to > re-allocate, we are already passed that point. >=20 > 2) When MD tries to read, it gets an error, so read from the other > mirror, or re-construct from parity/etc, and automatically attempt to > write to the sector, see point 1 above for the failure case. >=20 > So by the time MD gets a write error for a sector, the drive really is > bad, and MD can no longer ensure that *this* sector will be able to > properly store data again (whatever level of RAID we asked for, that > level can't be achieved with one drive faulty). So MD marks it bad, and > won't store any user data in that sector in future. As other drives are > replaced, we mark the corresponding sector on those drives as also bad, > so they also know that no user data should be stored there. >=20 > Eventually, we replace the faulty disk, and it would probably be safe to > store user data in the marked sector (assuming the new drive is not > faulty on the same sector, and all other member drives are not faulty on > the same sector). >=20 > So, to "fix" this, we just need a way to tell MD to try and write to all > member drives, on all faulty sectors, and if any drive returns fails to > write, then keep the sector as marked bad, if *ALL* drives succeed, then > remove from the bad blocks list on all members. >=20 > So why not add this feature to fix the problem, instead of throwing away > something that is potentially useful? Perhaps this could be done as part > of the "repair" mode, or done during a replace/add (when we reach the > "bad" sector, test the new drive, test all existing drives, and then > continue with the repair/add. >=20 > Would that solve the "bug"? I'd better want md to stop fixing "somebody else's problem", that is, the d= isk, and rather just do its job. As for the case, I have tried to manually = read those sectors named in the badblocks list and they all work. All of th= em. But then, there's no fixing, since they are proclaimed dead. So are the= ir siblings' sectors with the same number, regardless of status. If a drive has multiple issues with bad sector, kick it out. It doesn't hav= e anything to do in the RAID anymore Vennlig hilsen roy --=20 Roy Sigurd Karlsbakk (+47) 98013356 http://blogg.karlsbakk.net/ GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt -- Hi=C3=B0 g=C3=B3=C3=B0a skaltu =C3=AD stein h=C3=B6ggva, hi=C3=B0 illa =C3= =AD snj=C3=B3 rita.