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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 2FEAAC04EB8 for ; Tue, 4 Dec 2018 12:38:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E468B20878 for ; Tue, 4 Dec 2018 12:38:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Fosvd2Ua" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E468B20878 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726222AbeLDMio (ORCPT ); Tue, 4 Dec 2018 07:38:44 -0500 Received: from mail-io1-f65.google.com ([209.85.166.65]:40835 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725910AbeLDMio (ORCPT ); Tue, 4 Dec 2018 07:38:44 -0500 Received: by mail-io1-f65.google.com with SMTP id n9so13459999ioh.7 for ; Tue, 04 Dec 2018 04:38:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=jzBalv5q1STN9E6EgFkzMyPkte8Tt6vJGfT4i6jo/1Q=; b=Fosvd2Ua2/5gYPVQTBg9d5o9Pzt/2xg406iMUtNvm8BT4wRWH5c6z7U53ix/Npbwgd Aac6rqXv2YOBhEaHuwYKYZ4FF0B4SL8VA+Dlq48TYR6K5hzS+ejCxeinB2+xVmb/GhCN CBocOctQYNHyiAc6CMxbv4RodriDxc5Mtfky0CuGUWulQBfgsRLt848PsD2hkYYQ8toI wwAu9OxEuG90CluTZopaWb9ioi2yc0YHYOuQx9MPpqpg+DdA9XxTKNCVE9MwU6a4LgZB Z9WM06bAerTGQkww4zVBKY2EbXWDBXlR8Wyxt/U7R1JxSVMQ/xdYpsDY/GGHGMYufZVk FWxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=jzBalv5q1STN9E6EgFkzMyPkte8Tt6vJGfT4i6jo/1Q=; b=JWWJeh4SD02+8WR0RIYAvqRLTWr+kZE0fzO5JWy8b2bWWT5W/dJi5byObcNao+bQFF ysn1an1Ku/0bLu6/yIo3/Hpmfu5e0oAAseYHBnRxzCBKCikIefs57CyAxwTQQ38aXBIM KGARmbBKdkN2E+XOTSjqjaJ7vqWHtdEq9EFhxGRXT+yiaDoMrAbJ31MdjSv5rwbp+O2Z WwYwzaPq5HD22Gy6ndTZEyLYTn4xjpfTi7Ik4HFqAFojacgkNhwT4TeUqVyx41XIMNCj dmzqA5ooWO6FtR3v/ssPUsdWf93VQvhP//S/qP1r7KRBr+CQUFyHgFpe/CxEpLpFrWO2 fqTQ== X-Gm-Message-State: AA+aEWZdcPiXgh8pRAlVS55MOz5B0PtNYuAXUZn3xqJvbYWG3TtP4FtK m4u8h1qOTFpmwkHm85UYd54wah1Z2b8= X-Google-Smtp-Source: AFSGD/V4PS57b6JQhCGt24kRrsWj5BHGL/5rQrJ3HbJoFfw1PaUHYxRLWtQQovldGYnBEeoNt6a2/w== X-Received: by 2002:a5d:9602:: with SMTP id w2mr6254841iol.86.1543927122598; Tue, 04 Dec 2018 04:38:42 -0800 (PST) Received: from [191.9.209.46] (rrcs-70-62-41-24.central.biz.rr.com. [70.62.41.24]) by smtp.gmail.com with ESMTPSA id i78sm5485468itb.6.2018.12.04.04.38.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Dec 2018 04:38:41 -0800 (PST) Subject: Re: experiences running btrfs on external USB disks? To: Tomasz Chmielewski , Btrfs BTRFS References: From: "Austin S. Hemmelgarn" Message-ID: <7c8a85c7-52d8-202b-5bc7-0fa0c5c6e502@gmail.com> Date: Tue, 4 Dec 2018 07:38:38 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2018-12-04 00:37, Tomasz Chmielewski wrote: > I'm trying to use btrfs on an external USB drive, without much success. > > When the drive is connected for 2-3+ days, the filesystem gets remounted > readonly, with BTRFS saying "IO failure": > > [77760.444607] BTRFS error (device sdb1): bad tree block start, want > 378372096 have 0 > [77760.550933] BTRFS error (device sdb1): bad tree block start, want > 378372096 have 0 > [77760.550972] BTRFS: error (device sdb1) in __btrfs_free_extent:6804: > errno=-5 IO failure > [77760.550979] BTRFS info (device sdb1): forced readonly > [77760.551003] BTRFS: error (device sdb1) in > btrfs_run_delayed_refs:2935: errno=-5 IO failure > [77760.553223] BTRFS error (device sdb1): pending csums is 4096 > > > Note that there are no other kernel messages (i.e. that would indicate a > problem with disk, cable disconnection etc.). > > The load on the drive itself can be quite heavy at times (i.e. 100% IO > for 1-2 h and more) - can it contribute to the problem (i.e. btrfs > thinks there is some timeout somewhere)? > > Running 4.19.6 right now, but was experiencing the issue also with 4.18 > kernels. > > > > # btrfs device stats /data > [/dev/sda1].write_io_errs    0 > [/dev/sda1].read_io_errs     0 > [/dev/sda1].flush_io_errs    0 > [/dev/sda1].corruption_errs  0 > [/dev/sda1].generation_errs  0 It looks to me like the typical USB issues that are present with almost all filesystems but only seem to be noticed by BTRFS because it does more rigorous checking of data. In short, USB is _crap_ for fixed storage, don't use it like that, even if you are using filesystems which don't appear to complain.