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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BEFFC352A1 for ; Sat, 3 Dec 2022 18:04:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229629AbiLCSE3 (ORCPT ); Sat, 3 Dec 2022 13:04:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbiLCSE2 (ORCPT ); Sat, 3 Dec 2022 13:04:28 -0500 Received: from www18.qth.com (www18.qth.com [69.16.238.59]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF5931FFA2 for ; Sat, 3 Dec 2022 10:04:27 -0800 (PST) Received: from [73.207.192.158] (port=34930 helo=jpo) by www18.qth.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1p1WsF-00051B-7i for linux-raid@vger.kernel.org; Sat, 03 Dec 2022 12:04:27 -0600 Date: Sat, 3 Dec 2022 18:04:25 +0000 From: David T-G To: Linux RAID list Subject: batches and serial numbers (was "Re: md vs LVM and VMs and ...") Message-ID: <20221203180425.GU19721@jpo> Reply-To: Linux RAID list References: <20221124211019.GE19721@jpo> <512a4cdd-9013-e158-7c77-7409cd0dc3a1@youngman.org.uk> <20221125132259.GG19721@jpo> <20221125194932.GK19721@jpo> <20221128142422.GM19721@jpo> <20221203054130.GP19721@jpo> <1e419d58-46d8-affa-36dc-ef8c14760305@youngman.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1e419d58-46d8-affa-36dc-ef8c14760305@youngman.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - www18.qth.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - justpickone.org X-Get-Message-Sender-Via: www18.qth.com: authenticated_id: dmail@justpickone.org X-Authenticated-Sender: www18.qth.com: dmail@justpickone.org X-Source: X-Source-Args: X-Source-Dir: Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Anthony, et al -- ...and then Wols Lists said... % On 03/12/2022 05:41, David T-G wrote: % > % > The good news here is that I don't mix disk sizes; all of these are not % > only the same size but, for the foreseeable future, the exact same model. % % From the exact same batch? That's BAD news actually. I don't know about the same batch. I got three together, so maybe, and then I recently added a fourth. diskfarm:~ # for D in /dev/sd[bcdk] ; do printf "$D\t" ; smartctl -i $D | grep Serial ; done /dev/sdb Serial Number: 61U0A0HQFBKG /dev/sdc Serial Number: 61U0A0BEFBKG /dev/sdd Serial Number: 61U0A007FBKG /dev/sdk Serial Number: 91C0A03ZFBKG How close is too close for SNs? Anyone have a magic decoder ring? I seriously think I'm going to be asking for another -- plus the corresponding offsite external drive -- for Christmas, so we'll be even more homogeneous as time goes on and maybe sooner than later. % % Now that disk sizes have been standardised (and the number of actual % factories/manufacturers seriously reduced), it should be that a 1TB drive is % a 1TB drive is a 1TB drive. Decimal, that is, not binary. So there % *shouldn't* be any problems swapping one random drive out for another. That would be nice. But it just feels so ... WRONG! :-) I don't want to have to sweat different numbers of sectors or different caches or different speeds that will just make hiccups. I'm not yet sold on going multi-vendor all together ... [In different arrays or machines, certainly, but not when they're supposed to be identical members.] % % But if all your drives are the same make, model(, and batch), there is a not % insignificant risk they will all share the same defects, and fail at the % same time. It's accepted the risk is small, but it's there. What is the problem? Is it the manufacturer's firmware? Is it the day they were made? If I order a Tosh, a Seag, and a WD all on the same day then it sounds like I'm [much more] likely to get clones made at the same time in those few factories. But I couldn't just buy a drive a quarter and wait nearly a year to get up and running; I had to start somewhere ... % % It's why my raid is composed of a Seagate Barracuda 3TB (slap wrist, don't % use Barracudas!), 2 x 4TB Seagate Ironwolves, and 1 Toshiba 8TB N300. These are Tosh X300s, FWIW. Like 'em so far! % % Cheers, % Wol HAND :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt