[Bug 1758282] Re: [INTEL UBUNTU 18.04] RAID reshape hangs after OS reboot

[Launchpad Bug Tracker]

Status changed to 'Confirmed' because the bug affects multiple users.

** Changed in: mdadm (Ubuntu)
       Status: New => Confirmed

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Title:
  [INTEL UBUNTU 18.04] RAID reshape hangs after OS reboot

Status in mdadm package in Ubuntu:
  Confirmed

Bug description:
  Steps to reproduce:

  1. Create IMSM RAID container:
  mdadm --create /dev/md/imsm0 --metadata=imsm --raid-devices=3 /dev/sde /dev/sdc /dev/sdd --run
  2. Create IMSM RAID volume:
  mdadm --create /dev/md/r0d3s128h1_A --level=0 --chunk 128 --raid-devices=3 /dev/sde /dev/sdc /dev/sdd --run --assume-clean
  3. Add disk to container:
  mdadm --add /dev/md127 /dev/sdb
  4. Invoke RAID grow:
  export MDADM_EXPERIMENTAL=1;mdadm --grow /dev/md127 --raid-devices=4
  5. By cat /proc/mdstat we will see status of the reshape. 
  Also systemd unit file has been created: 

  cat /etc/systemd/system/mdadm-grow-continue at md127.service 
  #  This file is part of mdadm.
  #
  #  mdadm is free software; you can redistribute it and/or modify it
  #  under the terms of the GNU General Public License as published by
  #  the Free Software Foundation; either version 2 of the License, or
  #  (at your option) any later version.

  [Unit]
  Description=Manage MD Reshape on /dev/%I
  DefaultDependencies=no

  [Service]
  ExecStart=/sbin/mdadm --grow --continue /dev/%I
  #StandardInput=null
  #StandardOutput=null
  #StandardError=null
  KillMode=none

  And status of this service is:

  ● mdadm-grow-continue at md127.service - Manage MD Reshape on /dev/md127
     Loaded: loaded (/etc/systemd/system/mdadm-grow-continue at md127.service; static; vendor preset: enabled)
     Active: active (running) since Fri 2018-03-23 09:20:54 CET; 23s ago
   Main PID: 3364 (mdadm)
      Tasks: 1 (limit: 37710)
     CGroup: /system.slice/system-mdadm\x2dgrow\x2dcontinue.slice/mdadm-grow-continue at md127.service
             └─3364 /sbin/mdadm --grow --continue /dev/md127

  6. Reboot the platform.

  7. During OS booting I saw print:
  [   16.552076] md: reshape of RAID array md126

  8. After successfully boot we can see hanging reshape process (by cat
  /proc/mdstat).

  And status of the service:
  systemctl status mdadm-grow-continue at md127.service 
  ● mdadm-grow-continue at md127.service - Manage MD Reshape on /dev/md127
     Loaded: loaded (/etc/systemd/system/mdadm-grow-continue at md127.service; static; vendor preset: enabled)
     Active: inactive (dead)

  Possible workarounds:
  a) systemctl restart mdadm-grow-continue at md127.service
  or
  b) mdadm --grow --continue /dev/md127

  So the clue of the problem is in OS booting process and with correctly
  starting mdadm-grow-continue service.

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