From mboxrd@z Thu Jan 1 00:00:00 1970 From: Larkin Lowrey Subject: Unable to remove write journal device Date: Tue, 15 Aug 2017 11:41:06 -0400 Message-ID: <81af1a1e-ed4e-b080-ecbe-f2b0b8d0234b@nuclearwinter.com> References: <60abb68c-790b-42a0-3fbd-967b4cf877e5@nuclearwinter.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <60abb68c-790b-42a0-3fbd-967b4cf877e5@nuclearwinter.com> Content-Language: en-US Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids My understanding is that the current procedure to remove a write journal device is to first fail it then remove it. When I tried that mdadm hanged when I tried to remove the journal device. I'm running kernel 4.12.5-300.fc26.x86_64 and mdadm - v4.0 - 2017-01-09. My original objective was to test array reshaping with a journal device in use. My attempt to add a device failed so I decided to try removing the journal, doing a reshape, then re-adding the journal. What is the correct procedure for removing a journal device? Here's what I did... [root@build ~]# mdadm --readonly /dev/md1 [root@build ~]# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md1 : active (read-only) raid5 sdf1[5](S) sdb1[0] sdd1[3] sde1[4](J) sdc1[1] 4190208 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU] unused devices: [root@build ~]# mdadm /dev/md1 --fail /dev/sde1 mdadm: set /dev/sde1 faulty in /dev/md1 [root@build ~]# mdadm /dev/md1 --remove /dev/sde1 ...hangs here... The journal device is now marked failed but it isn't removed. [root@build ~]# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md1 : active (read-only) raid5 sdf1[5](S) sdb1[0] sdd1[3] sde1[4](J)(F) sdc1[1] 4190208 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU] unused devices: The following shows up in the logs: [ 393.707053] md/raid:md1: Disk failure on sde1, disabling device. md/raid:md1: Operation continuing on 3 devices. [ 393.714055] md/raid:md1: Disabling writeback cache for degraded array. --Larkin