7 Jun 2016

QNAP – How to repair RAID brokenness – Redux

by | posted in: Allgemein | 0 
[~] # /etc/init.d/services.sh stop

Unmount the volume
[~] # umount /dev/md0

Stop the array
[~] # mdadm -S /dev/md0
mdadm: stopped /dev/md0
Reassemble the volume
[~] # mdadm --assemble /dev/md0 /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3 /dev/sde3 /dev/sdf3
mdadm: /dev/md0 has been started with 5 drives (out of 6).
Wait, wha? What about that other disk that I think is okay?

[~] # mdadm --detail /dev/md0
/dev/md0:
Version : 00.90.03
Creation Time : Fri May 22 21:05:28 2009
Raid Level : raid5
[~] # cat /proc/mdstat


[~] # mdadm --add /dev/md0 /dev/sdb3

mdadm: re-added /dev/sdb3


[~] # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
md0 : active raid5 sdb3[6] sda3[0] sdf3[5] sde3[4] sdd3[3] sdc3[2]




The workaround is this:


    

  1. Telnet to NAS as Admin
    2. 

  2. Check your current disk configuration for Disk #1 and Disk #2 =
    
fdisk -l /dev/sda Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
    
255 heads, 63 sectors/track, 121601 cylinders
    
Units = cylinders of 16065 * 512 = 8225280 bytes
    

    Device Boot      Start         End      Blocks   Id  System
    
/dev/sdb1               1          66      530125   83  Linux
    
/dev/sdb2              67         132      530142   83  Linux
    
/dev/sdb3             133      121538   975193693   83  Linux
    
/dev/sdb4          121539      121600      498012   83  Linux
    

    fdisk -l /dev/sdb
    

    Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
    
255 heads, 63 sectors/track, 121601 cylinders
    
Units = cylinders of 16065 * 512 = 8225280 bytes
    

    Device Boot      Start         End      Blocks   Id  System
    
/dev/sda1               1          66      530125   83  Linux
    
/dev/sda2              67         132      530142   83  Linux
    
/dev/sda3             133      121538   975193693   83  Linux
    
/dev/sda4          121539      121600      498012   83  Linux
    3. 

  3. SDA is the first disk, SDB is the second disk
    4. 

  4. Verify the current status of RAID with this command =
    
mdadm –detail /dev/md0
    
/dev/md0:
    
Version : 00.90.03
    
Creation Time : Thu Sep 22 21:50:34 2011
    
Raid Level : raid1
    
Array Size : 486817600 (464.27 GiB 498.50 GB)
    
Used Dev Size : 486817600 (464.27 GiB 498.50 GB)
    
Raid Devices : 2
    
Total Devices : 1
    
Preferred Minor : 0
    
Persistence : Superblock is persistent
    

    Intent Bitmap : Internal
    

    Update Time : Thu Jul 19 01:13:58 2012
    
State : active, degraded
    
Active Devices : 1
    
Working Devices : 1
    
Failed Devices : 0
    
Spare Devices : 0
    

    UUID : 72cc06ac:570e3bf8:427adef1:e13f1b03
    
Events : 0.1879365
    

    Number   Major   Minor   RaidDevice State
    
0       0        0        0      removed
    
1       8        3        1      active sync  /dev/sda3
    5. 

  5. As you can see the /dev/sda3 is working, so disk #1 is OK, but disk #2 is missing from RAID
    6. 

  6. Check if Disk #2 /dev/sdb is mounted (it should be) =
    
mount/proc on /proc type proc (rw)
    
none on /dev/pts type devpts (rw,gid=5,mode=620)
    
sysfs on /sys type sysfs (rw)
    
tmpfs on /tmp type tmpfs (rw,size=32M)
    
none on /proc/bus/usb type usbfs (rw)
    
/dev/sda4 on /mnt/ext type ext3 (rw)
    
/dev/md9 on /mnt/HDA_ROOT type ext3 (rw)
    
/dev/md0 on /share/MD0_DATA type ext4 (rw,usrjquota=aquota.user,jqfmt=vfsv0,user_xattr,data=ordered,delalloc,noacl)
    
tmpfs on /var/syslog_maildir type tmpfs (rw,size=8M)
    
/dev/sdt1 on /share/external/sdt1 type ufsd (rw,iocharset=utf8,dmask=0000,fmask=0111,force)
    
tmpfs on /.eaccelerator.tmp type tmpfs (rw,size=32M)
    
/dev/sdb3 on /share/HDB_DATA type ext3 (rw,usrjquota=aquota.user,jqfmt=vfsv0,user_xattr,data=ordered,noacl)
    7. 

  7. Dismount the /dev/sdb3 Disk #2 with this command =
    
umount /dev/sdb3
    8. 

  8. Add Disk #2 into the RAID /dev/md0 =
    
mdadm /dev/md0 –add /dev/sdb3 mdadm: added /dev/sdb3
    9. 

  9. Check the RAID status and the rebuild should be started automatically =
    
mdadm –detail /dev/md0 /dev/md0:
    
Version : 00.90.03
    
Creation Time : Thu Sep 22 21:50:34 2011
    
Raid Level : raid1
    
Array Size : 486817600 (464.27 GiB 498.50 GB)
    
Used Dev Size : 486817600 (464.27 GiB 498.50 GB)
    
Raid Devices : 2
    
Total Devices : 2
    
Preferred Minor : 0
    
Persistence : Superblock is persistent
    

    Intent Bitmap : Internal
    

    Update Time : Thu Jul 19 01:30:27 2012
    
State : active, degraded, recovering
    
Active Devices : 1
    
Working Devices : 2
    
Failed Devices : 0
    
Spare Devices : 1
    

    Rebuild Status : 0% complete
    

    UUID : 72cc06ac:570e3bf8:427adef1:e13f1b03
    
Events : 0.1879848
    

    Number   Major   Minor   RaidDevice State
    
2       8       19        0      spare rebuilding   /dev/sdb3
    
1       8        3        1      active sync   /dev/sda3
    10. 

  10. Check the NAS site for the rebuild % progress
    11.