Missing Raid Slice

Discussion in 'Mac mini' started by eaglemick, Feb 3, 2015.

  1. eaglemick macrumors newbie

    Joined:
    Feb 3, 2015
    Location:
    Sydney, Australia
    #1
    Hi everyone, helping someone can help me with this problem!

    I have a Lacie 2big 4TB NAS connected via Thunderbolt to my mac mini which has suddenly stopped working.

    When I reboot the mac the drive lights up but does not appear in Finder. When I run disk utility the drive is listed as offline with a raid slice missing. I've tried repairing the disk to no avail. I've even tried demoting the raid slice but that operation failed also.

    Is there anything else I can do as I really don't want to loose the data now that I've converted all my cd's and movies to mp3!
     

    Attached Files:

  2. chabig macrumors 68040

    Joined:
    Sep 6, 2002
    #2
    It looks like one the drives failed. Unless you have a backup you've likely lost data.
     
  3. Celerondon macrumors 6502a

    Celerondon

    Joined:
    Oct 17, 2013
    Location:
    Southern Cal
    #3
    Built for Speed Rather Than Comfort?

    You asked for help but you did not mention RAID levels. Your array appears to be configured as RAID 0 (striped). This is fast but not safe. If it were instead configured as a RAID I (mirrored) set it would be safer but not nearly as fast. You can do both but that takes more $ because it requires more drives.
    http://www.thegeekstuff.com/2010/08/raid-levels-tutorial/

    If I am reading your Disk Utility screen correctly:
    RAID 0 = Data is gone(unless you can reanimate that drive)

    Did you need that much speed for CDs and movies?
     
  4. chabig macrumors 68040

    Joined:
    Sep 6, 2002
    #4
    He probably wanted the full 4GB of space.
     
  5. Celerondon macrumors 6502a

    Celerondon

    Joined:
    Oct 17, 2013
    Location:
    Southern Cal
    #5
    Right, I was just thinking about that factor. That is another aspect of the decision to use RAID 1. The mirrored arrays can cost more than twice as much for the same capacity with no performance increase.

    According to this thread there is a solution mentioned in the LaCie instruction manual:
    https://discussions.apple.com/thread/4899506

    I use another type of array for similar reasons every day. This Fusion Drive is larger and faster than the alternatives but there is an enhanced failure risk associated with this type of disk array. As with the RAID 0 drives, an elegant solution for the risk is one that we all should use - data backup. With Time Machine the FD is like any other storage. If any of your storage components fail, you simply replace the failed components and restore your files.
     
  6. Fishrrman macrumors G3

    Joined:
    Feb 20, 2009
    #6
    OP wrote:
    [[ Is there anything else I can do as I really don't want to loose the data now that I've converted all my cd's and movies to mp3! ]]

    Well, I guess this is a real-world example that validifies the clain that "RAID -is not- a backup" .... ?
     
  7. paulrbeers macrumors 68040

    Joined:
    Dec 17, 2009
    #7
    Well this is really more proof that RAID 0 is not RAID at all (redundant array of independent disks, there's no redundancy in RAID 0)....

    But true, RAID is not a backup and RAID 0 has no redundancy....

    EDIT: I use RAID 5 via SoftRaid for all of my storage needs with no real backup just redundancy. Why? Because if my house burns down, I have much bigger fish to fry than to worry about the movies and music stored on my drives (now all financial data is backed up).
     
  8. eaglemick thread starter macrumors newbie

    Joined:
    Feb 3, 2015
    Location:
    Sydney, Australia
    #8
    Thanks for the feedback.

    Yep, I went with the stripped set, raid 0, to maximise speed and storage space as I have tons of music and prefer the lossless format. I understand that means no backup hence why I am reaching out on here to see if there is a solution.

    I'll take a look at the highlighted thread and see if that helps.
     
  9. eaglemick thread starter macrumors newbie

    Joined:
    Feb 3, 2015
    Location:
    Sydney, Australia
    #9
    Still having issues

    I have taken one disk out of the drive enclosure and managed to reformat that with no problems.

    When I remove the formatted disk and try the same process with the other it doesn't read the disk at all. I can hear a clicking noise when the disk spins up on boot so I expect it is buggered unless anyone knows a way to save the disk still?
     
  10. Celerondon macrumors 6502a

    Celerondon

    Joined:
    Oct 17, 2013
    Location:
    Southern Cal
    #10
    Sorry friend!

    The disk that won't format is your problem. The only good news that I can give you is that you have not hurt anything by trying. Perhaps someone else has an idea but I that drive sounds dead to me.

    Your data is gone. The 50% of it that was on the good drive existed as an unrecoverable matrix.
     
  11. Natzoo macrumors 65816

    Natzoo

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    Sep 16, 2014
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    Not sure where i am
  12. eaglemick thread starter macrumors newbie

    Joined:
    Feb 3, 2015
    Location:
    Sydney, Australia
    #12
    Thanks Guys

    I've got Seagate drives in the Lacie bays so not a problem with the make I'd say. Just bad luck I guess.

    Going for a mirrored raid set this time as I'm not looking forward to ripping a couple of hundred CD's again :)
     

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