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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 74575C32771 for ; Mon, 27 Jan 2020 09:58:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46472214AF for ; Mon, 27 Jan 2020 09:58:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729253AbgA0J6q (ORCPT ); Mon, 27 Jan 2020 04:58:46 -0500 Received: from us.icdsoft.com ([192.252.146.184]:60904 "EHLO us.icdsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725845AbgA0J6q (ORCPT ); Mon, 27 Jan 2020 04:58:46 -0500 X-Greylist: delayed 398 seconds by postgrey-1.27 at vger.kernel.org; Mon, 27 Jan 2020 04:58:46 EST Received: (qmail 4371 invoked by uid 1001); 27 Jan 2020 09:52:05 -0000 Received: from 45.98.145.213.in-addr.arpa (HELO ?213.145.98.45?) (gnikolov@icdsoft.com@213.145.98.45) by 192.252.159.165 with ESMTPA; 27 Jan 2020 09:52:05 -0000 To: shli@kernel.org, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org From: Georgi Nikolov Subject: Pausing md check hangs Message-ID: <01ea67c2-244c-0427-0be7-c565fac97092@icdsoft.com> Date: Mon, 27 Jan 2020 11:52:03 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I posted a kernel bug about this a month ago but it did not receive any attention: https://bugzilla.kernel.org/show_bug.cgi?id=205929 Here is a copy of the bug report and I hope that this is the correct place to discuss this: I have a Supermicro server with 10 md raid6 arrays each consisting of 8 SATA drives. SATA drives are Hitachi/HGST Ultrastar 7K4000 8T. When i try to pause array check with "echo idle > "/sys/block//md/sync_action" it randomly hangs at different md device. Process "mdX_raid6" is at 100% cpu usage. cat /sys/block/mdX/md/journal_mode hungs forever. Here is the state at the moment of crash for one of the md devices: root@supermicro:/sys/block/mdX/md# find -mindepth 1 -maxdepth 1 -type f|sort|grep -v journal_mode|xargs -r egrep . ./array_size:default ./array_state:write-pending grep: ./bitmap_set_bits: Permission denied ./chunk_size:524288 ./component_size:7813895168 ./consistency_policy:resync ./degraded:0 ./group_thread_cnt:4 ./last_sync_action:check ./layout:2 ./level:raid6 ./max_read_errors:20 ./metadata_version:1.2 ./mismatch_cnt:0 grep: ./new_dev: Permission denied ./preread_bypass_threshold:1 ./raid_disks:8 ./reshape_direction:forwards ./reshape_position:none ./resync_start:none ./rmw_level:1 ./safe_mode_delay:0.204 ./skip_copy:0 ./stripe_cache_active:13173 ./stripe_cache_size:8192 ./suspend_hi:0 ./suspend_lo:0 ./sync_action:check ./sync_completed:3566405120 / 15627790336 ./sync_force_parallel:0 ./sync_max:max ./sync_min:1821385984 ./sync_speed:126 ./sync_speed_max:1000 (local) ./sync_speed_min:1000 (system) root@supermicro:~# cat /proc/mdstat Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md4 : active raid6 sdaa[2] sdab[3] sdy[0] sdae[6] sdac[4] sdad[5] sdaf[7] sdz[1] 46883371008 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/8] [UUUUUUUU] [====>................] check = 22.8% (1784112640/7813895168) finish=20571.7min speed=4884K/sec Regards, Georgi Nikolov