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=-3.8 required=3.0 tests=BAYES_00, 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 4B804C433B4 for ; Sat, 3 Apr 2021 16:12:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D55D610F7 for ; Sat, 3 Apr 2021 16:12:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236832AbhDCQMy convert rfc822-to-8bit (ORCPT ); Sat, 3 Apr 2021 12:12:54 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:36997 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230450AbhDCQMx (ORCPT ); Sat, 3 Apr 2021 12:12:53 -0400 Received: from [192.168.177.174] ([91.56.95.140]) by mrelayeu.kundenserver.de (mreue009 [213.165.67.97]) with ESMTPSA (Nemesis) id 1Mv2tE-1lkFo837JY-00r35Q; Sat, 03 Apr 2021 18:12:48 +0200 From: "Hendrik Friedel" To: "Chris Murphy" Subject: Re[6]: Filesystem sometimes Hangs Cc: "Chris Murphy" , "Btrfs BTRFS" Date: Sat, 03 Apr 2021 16:12:51 +0000 Message-Id: In-Reply-To: References: Reply-To: "Hendrik Friedel" User-Agent: eM_Client/8.1.1060.0 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K1:0LHYQ9ODnIyeIV2Xuz5wj16XVUWsBecN5I4ESe6I/4Op/KGKr6x KRhlfb8Kmd6iDNTe4GUM2psa/yCCLeyLLurJqSuYrw2J0A4UATxoLFBYJ+vGt1NhovBFq7m jcFt2AFqg8tuo2UxXvVgLTo09dKanTD4sWc0m28EnuPmm1MzfUahjXzEfwNjXGHvzG+LgW/ uue2AAVFu1QeDMEVKHxQg== X-UI-Out-Filterresults: notjunk:1;V03:K0:DEVGSq0ZjPY=:8QNyvsnKNx7KIqvBIiYADt G3Q6rj2hTZvVC2nLtxaG9/50/9u6gyijyMw2SOQwSQbUiFNaZ42+hAmymNfGnkWvYxJDRiRWs 0Z6eqQzFlPvPv14ADB7fXsAJU74D9L/iQy48PY31oHJmCNlFinIxhvDwaI7NYHRrzl7ybUqOt QzEqTE5vJIFkQ6UyYe2wBiVBBhVV6bdbjsrJ16RsgvWEZx5bAzm0/ZMJiHz9WFWmlyoxvC4Ea vTh73Ghv9BO+wdcHNvzFbgigktPwCrzhpCGKwHDXmvhxTvgwuS5QFidV2vn++Q25q47C4e2Ih dIUtLfqWfzh7ul+vUjPn8lM7wf4ZrxnNON0UrOPuO5FOp6eCHzUax2RcR7XYaNhry1L+qkZE1 4IQB5P92UYPY7FvCbRJ5sAno9tTcrkXTyGMkki5u7VYn7AEVtUitP88IxhggBwLZAwFl08GAT gHS1sQ/lLsYv93oze0RtntwveyeeDP3KVzi2jVq/FFiR17spOr2+ Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hello Chris, thanks for your reply. >> >Remove the discard mount option for this file system and see if that >> >fixes the problem. Run it for a week or two, or until you're certain >> >the problem is still happening (or certain it's gone). Some drives >> >just can't handle sync discards, they become really slow and hang, >> >just like you're reporting. >> >> In fstab, this option is not set: >> /dev/disk/by-label/DataPool1 /srv/dev-disk-by-label-DataPool1 >> btrfs noatime,defaults,nofail 0 2 > >You have more than one btrfs file system. Indeed: grep btrfs /dev/sdc2 on /srv/dev-disk-by-label-DockerImages type btrfs (rw,noatime,ssd,discard,space_cache,subvolid=5,subvol=/) /dev/sdd2 on /srv/dev-disk-by-label-Daten type btrfs (rw,relatime,ssd,space_cache,subvolid=5,subvol=/) /dev/sda1 on /srv/dev-disk-by-label-DataPool1 type btrfs (rw,noatime,space_cache,subvolid=5,subvol=/) You can see, that for sdc2 and sdd2, "ssd" is in the mount options. For sdc2 discard is present. I have not added this myelf. But it is in fstab. In fact, I got confused in my previous mail: sdc is an ssd and not the drive that I was experiencing problems with (well: The system was slow when accessing sda1. I cannot exclude, that this was caused by sdc2. >I'm suggesting not using >discard on any of them to try and narrow down the problem. Something >is turning on discards for sdc2, find it and don't use it for a while. Will do. > >> How do I deactivate discard then? >> These drives are spinning disks. I thought that discard is only relevant >> for SSDs? > >It's relevant for thin provisioning and sparse files too. But if sdc2 >is a HDD then the sync discard message isn't related to the problem, >but also makes me wonder why something is enabling sync discards on a >HDD? See above. It was my mistake, thinking it sdc2 was the spinning disc. >Anway I think you're on the right track to try 5.11.11 and if you >experience a hang again, use sysrq+w and that will dump the blocked >task trace into dmesg. Also include a description of the workload at >the time of the hang, and recent commands issued. Ok, will do. Thanks, Hendrik > > > > >-- >Chris Murphy