RAID6 with 5 drives only allows me to add one sparse drive

    • OMV 4.x
    • Resolved

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    • RAID6 with 5 drives only allows me to add one sparse drive

      Dear friends,

      i am running a OMV-Raid build with OMV3 and the switched to OMV4.
      The raid has 5 8GB disk drives used as a RAID6 device. The i decided
      to add another disk (same type same vedor), The disk appears in the
      drive but when i went to raid-menu and selected the raid and push the
      enlarge (vergrößern) Button the disk was added to the raid (as a sparse
      disk), so the capacity did not changed.

      How can i redraw this setting and use the drive hda as an active device
      extending the raid capacity?

      # mdadm --detail /dev/md127
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      /dev/md127:
      Version : 1.2
      Creation Time : Sat Jul 23 23:15:41 2016
      Raid Level : raid6
      Array Size : 23441685504 (22355.73 GiB 24004.29 GB)
      Used Dev Size : 7813895168 (7451.91 GiB 8001.43 GB)
      Raid Devices : 5
      Total Devices : 6
      Persistence : Superblock is persistent


      Intent Bitmap : Internal


      Update Time : Mon Jan 22 21:41:01 2018
      State : clean
      Active Devices : 5
      Working Devices : 6
      Failed Devices : 0
      Spare Devices : 1


      Layout : left-symmetric
      Chunk Size : 512K


      Name : woody:raiddev (local to host woody)
      UUID : e6001385:99d68308:36c78329:14720f1f
      Events : 14077


      Number Major Minor RaidDevice State
      0 8 16 0 active sync /dev/sdb
      1 8 32 1 active sync /dev/sdc
      2 8 48 2 active sync /dev/sdd
      3 8 64 3 active sync /dev/sde
      4 8 80 4 active sync /dev/sdf


      5 8 0 - spare /dev/sda
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


      Contents of /etc/mdadm/mdadm.conf:
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      DEVICE partitions

      # auto-create devices with Debian standard permissions
      CREATE owner=root group=disk mode=0660 auto=yes

      # automatically tag new arrays as belonging to the local system
      HOMEHOST <system>

      # definitions of existing MD arrays
      ARRAY /dev/md127 metadata=1.2 spares=1 name=woody:raiddev UUID=e6001385:99d68308:36c78329:14720f1f
      Contents of /etc/mdadm/mdadm.conf:
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


      cat /proc/partitions
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      major minor #blocks name

      259 0 244198584 nvme0n1
      259 1 235956224 nvme0n1p1
      259 2 1 nvme0n1p2
      259 3 8240128 nvme0n1p5
      8 0 7814026584 sda
      8 16 7814026584 sdb
      8 32 7814026584 sdc
      8 48 7814026584 sdd
      8 64 7814026584 sde
      8 80 7814026584 sdf
      9 127 23441685504 md127
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


      [Update-00]
      I followed this howto:ewams.net/?date=2014/03/29&vie…a_RAID6_volume_with_mdadm
      It looks like, that the command run until step6 (see result of mdadm --detail above).

      So the step 7 was outstanding:


      # mdadm -v --grow --raid-devices=5 /dev/md127

      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      mdadm: /dev/md127: no change requested
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


      The output looks strange to me. The mdadm told me, that there is no change. Can it be, that the process

      of enlarging take some time?


      [Update-01]
      According to this page, it may take some time ( a day ).
      ubuntuforums.org/showthread.php?t=2146170
      So i gonna leave a note tomorrow

      # echo check > /sys/block/md127/md/sync_action
      # cat /proc/mdstat
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10]
      md127 : active raid6 sda[5](S) sdf[4] sdc[1] sde[3] sdd[2] sdb[0]
      23441685504 blocks super 1.2 level 6, 512k chunk, algorithm 2 [5/5] [UUUUU]
      [>....................] check = 1.7% (138283584/7813895168) finish=690.6min speed=185228K/sec
      bitmap: 0/59 pages [0KB], 65536KB chunk
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

      [Update-02]
      Sad to say that this did not help at all. After remove add grow same situation.

      --> Help !!!

      The post was edited 7 times, last by GroovieMan ().

    • Ok, i solved that issue.

      For the first, OMV may did the same mistake, so i went on playing with the mdadm cli.
      The documentation of ewams.net/?date=2014/03/29&vie…RAID6_volume_with_mdadm#b
      is not correct. The error is in step 7:

      7 Expand the RAID6 array to include data on the new disk.
      root@debian:~# mdadm -v --grow --raid-devices=7 /dev/md0

      The argument 7 of param raid-devices=7 in in the spec is wrong it must be 8 !
      because it denotes the amount of devices to handle in the raid and not the disk
      number of:

      root@debian:~# mdadm --detail /dev/md0
      /dev/md0:
      Raid Level : raid6
      Array Size : 11721060352 (11178.07 GiB 12002.37 GB)
      Raid Devices : 6
      Total Devices : 7
      Persistence : Superblock is persistent
      State : clean
      Number Major Minor RaidDevice State
      0 8 32 0 active sync /dev/sdc
      1 8 48 1 active sync /dev/sdd
      2 8 80 2 active sync /dev/sdf
      4 8 96 3 active sync /dev/sdg
      5 8 112 4 active sync /dev/sdh
      6 8 16 5 active sync /dev/sdb
      7 8 0 - spare /dev/sda

      So my details of the raids is:
      # mdadm --detail /dev/md127
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

      [*] UUID : e6001385:99d68308:36c78329:14720f1f
      Events : 14119

      Number Major Minor RaidDevice State
      0 8 16 0 active sync /dev/sdb
      1 8 32 1 active sync /dev/sdc
      2 8 48 2 active sync /dev/sdd
      3 8 64 3 active sync /dev/sde
      4 8 80 4 active sync /dev/sdf

      5 8 0 - spare /dev/sda
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

      so there will be 6 disks and by this the mdadm grow should look like this:
      # mdadm -v --grow --raid-devices=6 /dev/md127

      Now when i ask the raid how it feels i got:
      # mdadm --detail /dev/md127
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      # mdadm --detail /dev/md127
      /dev/md127:
      Version : 1.2
      Creation Time : Sat Jul 23 23:15:41 2016
      Raid Level : raid6
      Array Size : 23441685504 (22355.73 GiB 24004.29 GB)
      Used Dev Size : 7813895168 (7451.91 GiB 8001.43 GB)
      Raid Devices : 6
      Total Devices : 6
      Persistence : Superblock is persistent


      Intent Bitmap : Internal


      Update Time : Thu Jan 25 08:26:35 2018
      State : clean, reshaping
      Active Devices : 6
      Working Devices : 6
      Failed Devices : 0
      Spare Devices : 0


      Layout : left-symmetric
      Chunk Size : 512K


      Reshape Status : 0% complete
      Delta Devices : 1, (5->6)


      Name : woody:raiddev (local to host woody)
      UUID : e6001385:99d68308:36c78329:14720f1f
      Events : 14147


      Number Major Minor RaidDevice State
      0 8 16 0 active sync /dev/sdb
      1 8 32 1 active sync /dev/sdc
      2 8 48 2 active sync /dev/sdd
      3 8 64 3 active sync /dev/sde
      4 8 80 4 active sync /dev/sdf
      5 8 0 5 active sync /dev/sda
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

      This is what i want and
      # cat /proc/mdstat
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10]
      md127 : active raid6 sda[5] sdc[1] sdd[2] sdb[0] sdf[4] sde[3]
      23441685504 blocks super 1.2 level 6, 512k chunk, algorithm 2 [6/6] [UUUUUU]
      [>....................] reshape = 0.3% (28559472/7813895168) finish=3012.3min speed=43073K/sec
      bitmap: 0/59 pages [0KB], 65536KB chunk

      unused devices: <none>
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

      Yeah, system is in state reshape, this is reasonalble and will take a day.
      Time to reshape myself and move to work too ;(

      I'll gonna leave a message to the above author.
    • Hi,

      right, raid-devices must be the full number of all drives inkl. the new one(s) ... so, if you upgrade from 5->6:
      mdadm --grow --raid-devices=6 /dev/mdX
      and if you upgrade from 5 to 8:
      mdadm --grow --raid-devices=8 /dev/mdX

      The -v switch turns on the verbose level ...

      After finishing the reshape, you have to "resize" your filesystem too.

      Sc0rp