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=-0.8 required=3.0 tests=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 295C4C433DF for ; Fri, 19 Jun 2020 09:32:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D73C2073E for ; Fri, 19 Jun 2020 09:32:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732110AbgFSJck convert rfc822-to-8bit (ORCPT ); Fri, 19 Jun 2020 05:32:40 -0400 Received: from len.romanrm.net ([91.121.86.59]:38498 "EHLO len.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731949AbgFSJbu (ORCPT ); Fri, 19 Jun 2020 05:31:50 -0400 Received: from natsu (unknown [IPv6:fd39::e99e:8f1b:cfc9:ccb8]) by len.romanrm.net (Postfix) with SMTP id 601744009F; Fri, 19 Jun 2020 09:31:48 +0000 (UTC) Date: Fri, 19 Jun 2020 14:31:48 +0500 From: Roman Mamedov To: Daniel Smedegaard Buus Cc: linux-btrfs@vger.kernel.org Subject: Re: Behavior after encountering bad block Message-ID: <20200619143148.1ec669e9@natsu> In-Reply-To: References: <20200619124505.586f2b63@natsu> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, 19 Jun 2020 10:08:43 +0200 Daniel Smedegaard Buus wrote: > Well, that's why I wrote having the *data* go bad, not the drive But data going bad wouldn't pass unnoticed like that (with reads resulting in bad data), since drives have end-to-end CRC checking, including on-disk and through the SATA interface. If data on-disk is somehow corrupted, that will be a CRC failure on read, and still an I/O error for the host. I only heard of some bad SSDs (SiliconMotion-based) returning corrupted data as if nothing happened, and only when their flash lifespan is close to depletion. > even though either scenario should still effectively end up yielding the > same behavior from btrfs I believe that's also an assumption you'd want to test, if you want to be through in verifying its behavior on failures or corruptions. And anyways it's better to set up a scenario which is as close as possible to ones you'd get in real-life. > But check out my retraction reply from earlier — it was just me being stupid > and forgetting to use conv=notrunc on my dd command used to damage the > loopback file :) Sure, I only commented on the part where it still made sense. :) -- With respect, Roman