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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,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 AB640C388F9 for ; Tue, 3 Nov 2020 20:41:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C25B223AC for ; Tue, 3 Nov 2020 20:41:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730313AbgKCUlI convert rfc822-to-8bit (ORCPT ); Tue, 3 Nov 2020 15:41:08 -0500 Received: from mout.kundenserver.de ([217.72.192.73]:51043 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730300AbgKCUlG (ORCPT ); Tue, 3 Nov 2020 15:41:06 -0500 Received: from [192.168.177.174] ([91.63.191.240]) by mrelayeu.kundenserver.de (mreue106 [213.165.67.113]) with ESMTPSA (Nemesis) id 1Ma1D8-1koKqo34tg-00VwZC; Tue, 03 Nov 2020 21:40:30 +0100 From: "Hendrik Friedel" To: "Zygo Blaxell" , lakshmipathi.ganapathi@collabora.com Subject: Re[2]: parent transid verify failed: Fixed but re-appearing Cc: "Btrfs BTRFS" Date: Tue, 03 Nov 2020 20:40:40 +0000 Message-Id: In-Reply-To: <20201103194045.GB28049@hungrycats.org> References: <20201021134635.GT5890@hungrycats.org> <20201021193246.GE21815@hungrycats.org> <20201021212229.GF21815@hungrycats.org> <20201021213854.GG21815@hungrycats.org> <20201103194045.GB28049@hungrycats.org> Reply-To: "Hendrik Friedel" User-Agent: eM_Client/8.0.3385.0 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K1:aUGDKZLIYT0M7ln2X35KffGtM5m2z3nhJ6eWJ4iETnsPXBTgpSW 4d8tEu89RO+dwCEXngYrz0v/k2MFD2x2x+mm/0q5LYkf4GEtVVUR+AenZi4rOJdBC/JcImc GTOrFwCEB70P3haQamikCfGL6xVtJRyx7rnIYmFOHDivMhDKdONbe0Y+cEA2aOPX3Jd18nZ jR5R8u6YrKTBSWJmMmTRQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:7nrBFJZPP7E=:Mwi2yZfIcGV3di+PZiLO2k ZOZzd46tec+QEe7iLRNrKgss+xvcEW+ve1zK3l4DhCNjd0ZfiDxss/EztxZcD6rHEL2KUJHvX KNBw4VDKWyoTxbUaF76gjAuuGlrCGjzB1cFr1wBFzdMyY9Q+vweHEM6jvlSyNEKO8+iAKPC6A RMAM5ir+9k47HTfHLA+KoYTPOvT+0hneD5vwZT43HjKACL6xygSbIF3ssMxcQslNIR7PV4DDm KuTPFb/LaktPPNSFgNk8p+uozz/gfADcxq+cVIDPungBGOWb9mY9Sf80YE2X/QPSv0SaGGUMf MHWvvtpt7MiRv1Opj97sdi7HK0ijnbcPC5fH9NJy1PWfrcvFJf8PLO3VgpSz6DD6lHjYwY7Aa PoC0f2hvi11aOO3xejKvyxqDBzyvvII+zq/t7my2MURVFt4SYFOP2KB60f5JIzNf4BDzW/436 xAbTj1Havw== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hello Zygo, hello Lakshmipathi, @Lakshmipathi: as you suggested I consulted the BTRFS-Mailing list on this issue: https://github.com/Lakshmipathi/dduper/issues/39 Zygo was so kind to help me and he suspects the error to lie within dduper. >> > > Sure, more scrubs are better. They are supposed to be run regularly >> > > to detect drives going bad. >> > btrfs scrub start -Bd /dev/sda1 >> > >> > >> > scrub device /dev/sda1 (id 1) done >> > scrub started at Wed Oct 21 23:38:36 2020 and finished after 13:45:29 >> > total bytes scrubbed: 6.56TiB with 0 errors >> > >> > But then again: >> > dduper --device /dev/sda1 --dir /srv/dev-disk-by-label-DataPool1/dduper_test/testfiles -r --dry-run >> > parent transid verify failed on 16500741947392 wanted 358407 found 358409 >> > Ignoring transid failure > >Wait...is that the kernel log, or the output of the dduper command? > It is on the commandline once I run the command; thus I suspect it is the dduper output. But of course sometimes the Kernel-Messages appear directly on the commandline. I do not know how to tell. > >commit 3e5f67f45b553045a34113cafb3c22180210a19f (tag: v0.04, origin/dockerbuild) >Author: Lakshmipathi >Date: Fri Sep 18 11:51:42 2020 +0530 > >file deduper: > > 194 def btrfs_dump_csum(filename): > 195 global device_name > 196 > 197 btrfs_bin = "/usr/sbin/btrfs.static" > 198 if os.path.exists(btrfs_bin) is False: > 199 btrfs_bin = "btrfs" > 200 > 201 out = subprocess.Popen( > 202 [btrfs_bin, 'inspect-internal', 'dump-csum', filename, device_name], > 203 stdout=subprocess.PIPE, > 204 close_fds=True).stdout.readlines() > 205 return out > >OK there's the problem: it's dumping csums from a mounted filesystem by >reading the block device instead of using the TREE_SEARCH_V2 ioctl. >Don't do that, because it won't work. ;) I trust you on this ;-) But I am surprised I am the only one reporting this issue. Will it *always* not work, or does it not work in some cases and my situation is making it extremely unlikely to work? > >The "parent transid verify failed" errors are harmless. They are due >to the fact that a process reading the raw block device can never build >an accurate model of a live filesystem that is changing underneathi it. > >If you manage to get some dedupe to happen, then that's a bonus. > > >> > >> > > > Anything else, I can do? >> > > >> > > It looks like sda1 might be bad and it is working by replacing lost >> > > data from the mirror on sdj. But this replacement should be happening >> > > automatically on read (and definitely on scrub), so you shouldn't ever >> > > see the same error twice, but it seems that you do. >> > >> > Well, it is not the same error twice. > >Earlier you quoted some duplicate lines. Normally those get fixed after the >first line, so you never see the second. > I see. Regards, Hendrik