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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 0E577C282D5 for ; Wed, 30 Jan 2019 08:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9CAC21473 for ; Wed, 30 Jan 2019 08:50:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730224AbfA3IuS (ORCPT ); Wed, 30 Jan 2019 03:50:18 -0500 Received: from len.romanrm.net ([91.121.75.85]:47248 "EHLO len.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725850AbfA3IuS (ORCPT ); Wed, 30 Jan 2019 03:50:18 -0500 X-Greylist: delayed 477 seconds by postgrey-1.27 at vger.kernel.org; Wed, 30 Jan 2019 03:50:17 EST Received: from natsu (unknown [IPv6:fd39::e99e:8f1b:cfc9:ccb8]) by len.romanrm.net (Postfix) with SMTP id E209E2038B; Wed, 30 Jan 2019 08:42:19 +0000 (UTC) Date: Wed, 30 Jan 2019 13:42:19 +0500 From: Roman Mamedov To: Hans van Kranenburg Cc: linux-btrfs Subject: Re: dm-integrity + mdadm + btrfs = no journal? Message-ID: <20190130134219.13a4b558@natsu> In-Reply-To: <2a321782-d258-1ef3-8d25-149b8e24e819@mendix.com> References: <2a321782-d258-1ef3-8d25-149b8e24e819@mendix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, 29 Jan 2019 23:15:18 +0000 Hans van Kranenburg wrote: > So, what I was thinking of is: > > * Use dm-integrity on partitions on the individual disks > * Use mdadm RAID10 on top (which is then able to repair bitrot) > * Use LVM on top > * Etc... You never explicitly say what's the whole idea, what are you protecting against. By mentions of bitrot and of dm-integrity, you seem to think that when hardware is "starting to fall apart" the disks will eventually start returning wrong/corrupt data. Thing is, they do not. What you will get on disks going bad is uncorrectable read errors (UNC), not a silent corruption. The latter is still possible, but more likely to be caused by the SATA controller issues (or its driver/firmware), not disks. And those are hardly related to whether it's "new" or "old". -- With respect, Roman