wiki:TipAndDoc/storage/RAID/failure

Version 7 (modified by mitty, 15 years ago) (diff)

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  1. failure test
    1. 初期状態
    2. hot-remove spare disk
    3. fail, remove and re-add
      1. recovering
    4. reboot with degraded 1 disk
  2. hardware failure test
    1. 初期状態
    2. disconnect /dev/sdb and reboot

failure test

初期状態

  • cat /proc/mdstat 
    Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda2[0] sdc1[2](S) sdb2[1]
      1461760 blocks [2/2] [UU]

md0 : active raid0 sda1[0] sdb1[1]
      192512 blocks 64k chunks

unused devices: <none>
  • sudo mdadm -D /dev/md1 
    /dev/md1:
        Version : 00.90.03
  Creation Time : Thu Jun 11 22:27:07 2009
     Raid Level : raid1
     Array Size : 1461760 (1427.74 MiB 1496.84 MB)
  Used Dev Size : 1461760 (1427.74 MiB 1496.84 MB)
   Raid Devices : 2
  Total Devices : 3
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Fri Jun 12 02:21:57 2009
          State : clean
 Active Devices : 2
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 1

           UUID : 79c3f25a:e47a02f3:9bb41f43:b191cd1a
         Events : 0.5

    Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2

       2       8       33        -      spare   /dev/sdc1

hot-remove spare disk

  • sudo mdadm /dev/md1 -r /dev/sdc1 
    mdadm: hot removed /dev/sdc1
    • sudo mdadm -D /dev/md1 
          Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2
  • sudo mdadm /dev/md1 -a /dev/sdc1 
    mdadm: re-added /dev/sdc1
    • sudo mdadm -D /dev/md1 
          Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2

       2       8       33        -      spare   /dev/sdc1

fail, remove and re-add

  • man mdadm 
    MANAGE MODE
       Usage: mdadm device options... devices...

       This usage will allow individual devices in  an  array  to  be  failed,
       removed  or  added.  It is possible to perform multiple operations with
       on command. For example:
         mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1
       will firstly mark /dev/hda1 as faulty in /dev/md0 and will then  remove
       it  from the array and finally add it back in as a spare.  However only
       one md array can be affected by a single command.

  • sudo mdadm /dev/md1 -f /dev/sda2 -r /dev/sda2 -a /dev/sda2 
    mdadm: set /dev/sda2 faulty in /dev/md1
mdadm: hot removed /dev/sda2
mdadm: re-added /dev/sda2
    • cat /proc/mdstat 
      Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda2[2](S) sdc1[3] sdb2[1]
      1461760 blocks [2/1] [_U]
      [>....................]  recovery =  0.5% (8448/1461760) finish=2.8min speed=8448K/sec

md0 : active raid0 sda1[0] sdb1[1]
      192512 blocks 64k chunks

unused devices: <none>
    • sudo mdadm -D /dev/md1 
      /dev/md1:
        Version : 00.90.03
  Creation Time : Thu Jun 11 22:27:07 2009
     Raid Level : raid1
     Array Size : 1461760 (1427.74 MiB 1496.84 MB)
  Used Dev Size : 1461760 (1427.74 MiB 1496.84 MB)
   Raid Devices : 2
  Total Devices : 3
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Fri Jun 12 02:28:20 2009
          State : clean, degraded, recovering
 Active Devices : 1
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 2

 Rebuild Status : 8% complete

           UUID : 79c3f25a:e47a02f3:9bb41f43:b191cd1a
         Events : 0.17

    Number   Major   Minor   RaidDevice State
       3       8       33        0      spare rebuilding   /dev/sdc1
       1       8       18        1      active sync   /dev/sdb2

       2       8        2        -      spare   /dev/sda2

recovering

  • dmesg 
    [ 6932.978126] raid1: Disk failure on sda2, disabling device.
[ 6932.978134]  Operation continuing on 1 devices
[ 6932.994568] RAID1 conf printout:
[ 6932.994603]  --- wd:1 rd:2
[ 6932.995107]  disk 0, wo:1, o:0, dev:sda2
[ 6932.995127]  disk 1, wo:0, o:1, dev:sdb2
[ 6933.022454] RAID1 conf printout:
[ 6933.022462]  --- wd:1 rd:2
[ 6933.022476]  disk 1, wo:0, o:1, dev:sdb2
[ 6933.056753] RAID1 conf printout:
[ 6933.056758]  --- wd:1 rd:2
[ 6933.056762]  disk 0, wo:1, o:1, dev:sdc1
[ 6933.056764]  disk 1, wo:0, o:1, dev:sdb2
[ 6933.061349] md: recovery of RAID array md1
[ 6933.061379] md: minimum _guaranteed_  speed: 1000 KB/sec/disk.
[ 6933.061403] md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for recovery.
[ 6933.062332] md: using 128k window, over a total of 1461760 blocks.
[ 6933.173690] md: unbind<sda2>
[ 6933.173708] md: export_rdev(sda2)
[ 6933.945635] md: bind<sda2>
[ 7066.932827] md: md1: recovery done.
[ 7067.055469] RAID1 conf printout:
[ 7067.055475]  --- wd:2 rd:2
[ 7067.055479]  disk 0, wo:0, o:1, dev:sdc1
[ 7067.055481]  disk 1, wo:0, o:1, dev:sdb2
  • cat /proc/mdstat 
    Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda2[2](S) sdc1[0] sdb2[1]
      1461760 blocks [2/2] [UU]

md0 : active raid0 sda1[0] sdb1[1]
      192512 blocks 64k chunks

unused devices: <none>
  • sudo mdadm -D /dev/md1 
    /dev/md1:
        Version : 00.90.03
  Creation Time : Thu Jun 11 22:27:07 2009
     Raid Level : raid1
     Array Size : 1461760 (1427.74 MiB 1496.84 MB)
  Used Dev Size : 1461760 (1427.74 MiB 1496.84 MB)
   Raid Devices : 2
  Total Devices : 3
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Fri Jun 12 02:31:09 2009
          State : active
 Active Devices : 2
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 1

           UUID : 79c3f25a:e47a02f3:9bb41f43:b191cd1a
         Events : 0.45

    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       1       8       18        1      active sync   /dev/sdb2

       2       8        2        -      spare   /dev/sda2

reboot with degraded 1 disk

  • sudo mdadm /dev/md1 -f /dev/sdc1 /dev/sda2 
    mdadm: set /dev/sdc1 faulty in /dev/md1
mdadm: set /dev/sda2 faulty in /dev/md1
  • sudo mdadm /dev/md1 -r /dev/sdc1 /dev/sda2 
    mdadm: hot removed /dev/sdc1
mdadm: hot removed /dev/sda2
    • sudo mdadm -D /dev/md1 
          Number   Major   Minor   RaidDevice State
       0       0        0        0      removed
       1       8       18        1      active sync   /dev/sdb2
  • sudo reboot
    • /dev/sdb2 のみで正常に起動する

hardware failure test

初期状態

  • cat /proc/mdstat 
    Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda2[0] sdc1[2](S) sdb2[1]
      1461760 blocks [2/2] [UU]

md0 : active raid0 sda1[0] sdb1[1]
      192512 blocks 64k chunks

unused devices: <none>

disconnect /dev/sdb and reboot

  • attachment:ubuntu-raid-1.png​
    • この状態で4分ほど停止 (タイムアウト待ち？)
    • sdbを物理的に切断したため、再起動前にsdcとして認識されていたディスクがsdbとして認識されている
      • [ 22.498171] sdb: sdb1 となっているのはそのせい
      • VMware 仮想SCSIデバイスとして接続しているため？
  • attachment:ubuntu-raid-2.png​
    • 10秒ほど選択肢が表示される
  • attachment:ubuntu-raid-3.png​
    • デフォルトでは、BusyBox shellに落ちる
  • bootloaderにGRUBを使っている場合は、ミラーのMBRにもGRUBをインストールしておく必要がある

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