Results 1 to 3 of 3

Thread: Help recovering a RAID 5 array

  1. #1
    Join Date
    Jul 2010
    Beans
    2

    Exclamation Help recovering a RAID 5 array

    Hello,

    I'm a nube to linux and Ubuntu but have found that it is a solution to a problem I have.

    I have a Buffalo Terastation NAS that started to report bad sectors. It was setup RAID 5 with 4 1 terabyte drives. I went to replace the drive and everything went down hill. The array somehow ended up being corrupt. After much research and playing around I've found I can access the folders/files of the array using Ubuntu. I pulled the drives from the NAS and attached them to my workstation and loaded Ubuntu. After loading up the drives in Ubuntu I was able to start the array and mount it. It was degraded but recovering. I could see all my files and folders. Needless to say I was thrilled until... One of the other drives reported as faulty. So I have a RAID 5 array with 2 faulty drives. Usually I would say I'm screwed and forget trying to recover my data however I know the drives are only faulty because of bad sectors and not mechanical. Also I have been able to load them up 3 times and start the copy process off onto another system. It will run for some time and then the second drives reports faulty and bam I'm back down.

    Here is my question: Is there a way I can force the array to stay up (in maybe even a read-only mode) long enough for me to capture my files? Or is there a way I can repair the drives so that all is good? Each time I have been able to get data off the drives I have to uninstall ubuntu and reinstall it and then create the array again. If I can't get the drives to stay online even in a faulty state then is there an easy way for me to tear down the array and reset the status of the drives/array and bring it back online?


    Keep in mind I'm very new to the linux world. I've been messing with this for two weeks and I think it's time to ask for some help which I hate to do. In my 2 weeks if messed around with mdadm, xfs_repair, fsck, fdisk and have somewhat of an understanding of what they do however it seems like everything I run one of the tools I always end up with some sort of superblock error. I think I may have also ended up with an extra partition on each disk as well as disks belonging to multiple arrays. but I know if I wanted to I could still get it back up long enough to get 3GB of data or so before it fails again.


    Some output that may be useful.

    root@ubuntu:~# fdisk -l

    Disk /dev/sda: 82.3 GB, 82348277760 bytes
    255 heads, 63 sectors/track, 10011 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x39b7cbe9

    Device Boot Start End Blocks Id System
    /dev/sda1 * 1 10010 80405293+ 7 HPFS/NTFS

    Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x00000000

    Device Boot Start End Blocks Id System
    /dev/sdb1 1 37 297171 83 Linux
    /dev/sdb2 38 99 498015 83 Linux
    /dev/sdb4 100 121601 975964815 5 Extended
    /dev/sdb5 100 116 136521 82 Linux swap / Solaris
    /dev/sdb6 117 121572 975595288+ 83 Linux

    Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x00000000

    Device Boot Start End Blocks Id System
    /dev/sdc1 1 37 297171 83 Linux
    /dev/sdc2 38 99 498015 83 Linux
    /dev/sdc4 100 121601 975964815 5 Extended
    /dev/sdc5 100 116 136521 82 Linux swap / Solaris
    /dev/sdc6 117 121572 975595288+ 83 Linux

    Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x00000000

    Device Boot Start End Blocks Id System
    /dev/sdd1 1 37 297171 83 Linux
    /dev/sdd2 38 99 498015 83 Linux
    /dev/sdd4 100 121601 975964815 5 Extended
    /dev/sdd5 100 116 136521 82 Linux swap / Solaris
    /dev/sdd6 117 121572 975595288+ 83 Linux

    Disk /dev/sde: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x00000000

    Device Boot Start End Blocks Id System
    /dev/sde1 1 37 297171 83 Linux
    /dev/sde2 38 99 498015 83 Linux
    /dev/sde4 100 121601 975964815 5 Extended
    /dev/sde5 100 116 136521 82 Linux swap / Solaris
    /dev/sde6 117 121572 975595288+ 83 Linux


    root@ubuntu:~# mdadm --examine /dev/sdb6
    /dev/sdb6:
    Magic : a92b4efc
    Version : 00.90.00
    UUID : a9a636f3:4122e808:84c227cc:8c8dc586
    Creation Time : Sun May 24 11:05:33 2009
    Raid Level : raid5
    Used Dev Size : 975595200 (930.40 GiB 999.01 GB)
    Array Size : 2926785600 (2791.20 GiB 2997.03 GB)
    Raid Devices : 4
    Total Devices : 4
    Preferred Minor : 2

    Update Time : Tue Jul 13 22:10:36 2010
    State : clean
    Active Devices : 2
    Working Devices : 2
    Failed Devices : 1
    Spare Devices : 0
    Checksum : 796b7307 - correct
    Events : 30706218

    Layout : left-symmetric
    Chunk Size : 64K

    Number Major Minor RaidDevice State
    this 2 8 22 2 active sync /dev/sdb6

    0 0 0 0 0 removed
    1 1 8 38 1 active sync /dev/sdc6
    2 2 8 22 2 active sync /dev/sdb6
    3 3 0 0 3 faulty removed
    root@ubuntu:~# mdadm --examine /dev/sdc6
    /dev/sdc6:
    Magic : a92b4efc
    Version : 00.90.00
    UUID : a9a636f3:4122e808:84c227cc:8c8dc586
    Creation Time : Sun May 24 11:05:33 2009
    Raid Level : raid5
    Used Dev Size : 975595200 (930.40 GiB 999.01 GB)
    Array Size : 2926785600 (2791.20 GiB 2997.03 GB)
    Raid Devices : 4
    Total Devices : 4
    Preferred Minor : 2

    Update Time : Tue Jul 13 22:10:36 2010
    State : clean
    Active Devices : 2
    Working Devices : 2
    Failed Devices : 1
    Spare Devices : 0
    Checksum : 796b7315 - correct
    Events : 30706218

    Layout : left-symmetric
    Chunk Size : 64K

    Number Major Minor RaidDevice State
    this 1 8 38 1 active sync /dev/sdc6

    0 0 0 0 0 removed
    1 1 8 38 1 active sync /dev/sdc6
    2 2 8 22 2 active sync /dev/sdb6
    3 3 0 0 3 faulty removed

    root@ubuntu:~# mdadm --examine /dev/sdd6
    /dev/sdd6:
    Magic : a92b4efc
    Version : 00.90.00
    UUID : a9a636f3:4122e808:84c227cc:8c8dc586
    Creation Time : Sun May 24 11:05:33 2009
    Raid Level : raid5
    Used Dev Size : 975595200 (930.40 GiB 999.01 GB)
    Array Size : 2926785600 (2791.20 GiB 2997.03 GB)
    Raid Devices : 4
    Total Devices : 4
    Preferred Minor : 2

    Update Time : Tue Jul 13 21:57:23 2010
    State : clean
    Active Devices : 3
    Working Devices : 4
    Failed Devices : 0
    Spare Devices : 1
    Checksum : 796b6fc8 - correct
    Events : 30706190

    Layout : left-symmetric
    Chunk Size : 64K

    Number Major Minor RaidDevice State
    this 4 8 54 4 spare /dev/sdd6

    0 0 0 0 0 removed
    1 1 8 38 1 active sync /dev/sdc6
    2 2 8 22 2 active sync /dev/sdb6
    3 3 8 70 3 active sync /dev/sde6
    4 4 8 54 4 spare /dev/sdd6

    root@ubuntu:~# mdadm --examine /dev/sde6
    /dev/sde6:
    Magic : a92b4efc
    Version : 00.90.00
    UUID : a9a636f3:4122e808:84c227cc:8c8dc586
    Creation Time : Sun May 24 11:05:33 2009
    Raid Level : raid5
    Used Dev Size : 975595200 (930.40 GiB 999.01 GB)
    Array Size : 2926785600 (2791.20 GiB 2997.03 GB)
    Raid Devices : 4
    Total Devices : 4
    Preferred Minor : 2

    Update Time : Tue Jul 13 21:57:23 2010
    State : clean
    Active Devices : 3
    Working Devices : 4
    Failed Devices : 0
    Spare Devices : 1
    Checksum : 796b6fdc - correct
    Events : 30706190

    Layout : left-symmetric
    Chunk Size : 64K

    Number Major Minor RaidDevice State
    this 3 8 70 3 active sync /dev/sde6

    0 0 0 0 0 removed
    1 1 8 38 1 active sync /dev/sdc6
    2 2 8 22 2 active sync /dev/sdb6
    3 3 8 70 3 active sync /dev/sde6
    4 4 8 54 4 spare /dev/sdd6

  2. #2
    Join Date
    Apr 2009
    Location
    Texas
    Beans
    Hidden!
    Distro
    Ubuntu 12.04 Precise Pangolin

    Re: Help recovering a RAID 5 array

    For starters i would get solid harddrives before reconstructing raid. This should get you started.
    Ubuntu Christian Edition chat on irc at server: OFTC/channel: #ubuntuCE
    BootInfoScript DualBooting
    Grub Grub2 MBR/GRUB
    Boot Info Script courtesy of community member meierfra and ghulselmans

  3. #3
    Join Date
    Jul 2010
    Beans
    2

    Re: Help recovering a RAID 5 array

    I suppose I could try to assemble the array again from scratch and a new disk and see if it will resync the array on the new disk before it faults out again. Question is do I run the risk of corrupting more data if I do. If it gets me no where could I throw the drive that was bad back in and proceed coping 3GB at a time?

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •