Hard Drive RAID Help

Discussion in 'Mac Pro' started by mildewproductio, Dec 20, 2007.

  1. mildewproductio macrumors newbie

    Dec 20, 2007
    Ok we are having a problem with our Hard Drives that are part of a RAID. We are connected to a G4 Tower, running OS 10.4.11.

    We have 4 120GB Hard Drives in set up in a RAID.

    Now all of the sudden the mac won't mount the RAID. I open Disk Utility and it only sees 2 of the 120GB hard drives, and says they are offline (I'm guessing because it needs the other 2 drives in the RAID).

    The way it's hooked up inside is that 2 hard drives are connected to one part of the mother board, and the other 2 to another part of the mother board.

    Through problem solving I figured out which 2 were being seen and which 2 were not being seen. So I took the 2 that were not being seen and used the power connecters and connecting ribbon from the drive that was being seen and plugged it into the mother board slot that was being seen. Doing this the Mac still did not detect the 2 bad drives.

    We plugged the 2 good drives into the mother board slot that wasn't seeing the 2 other drives, and it did see the 2 good drives.

    To me this says, it isn't the mother board slot, it isn't the ribbon, and it isn't the power connector.

    However, if the drives were bad wouldn't the Mac be able to at least see them, and just give an error that they cannot read them?

    Anyone have any suggestions?
  2. Consultant macrumors G5


    Jun 27, 2007
    You are probably using RAID 0, but you need to provide RAID info.

    If you are using RAID 0, you know the risks.
  3. mildewproductio thread starter macrumors newbie

    Dec 20, 2007
    Actually I don't know the risks. I didn't set this RAID up, it was set up before I started working here 3 and a half years ago. I'm a video editor/director, and I don't really know a lot about RAIDS. Just trying to figure out this problem.

    What info would you need? Would it matter if it was RAID 0 for the Mac to not be able to see the hard drives?
  4. diamond.g macrumors 603


    Mar 20, 2007
    If a drive dies in a RAID 0 configuration you have lost all the data across all drives. If it is a mirror then you should still be able to run, but since it seems like you can't see the array you may have either a RAID 0 or RAID 5.
  5. alex1 macrumors newbie

    Dec 19, 2007
    Ouch... Well.. hopefully it's the power supply or something not spinning up in a minimum amount of time.. (happened to me a couple times)... try unplugging everything and powering up cold. Try it 10 or 15 times. If it mounts... IMEADITLY (spelling?) copy everything over to a known good drive (firewire/USB/SATA/network/anything and consider yourself lucky. If it never mounts, the odds are not good. $100's to $1,000's to recover data. Raid 0 with 4 drives isn't the smartest thing in the world. Raid 0+1 or one of many other drive scheems options are a lot smarter.. The remainder drive would be a constant backup incase of drive failure. With RAID 0 any failure of ANY drive means data flow is lost on all drives, and the odds are not good/cheap for recovery. IF you must use RAID 0, make frequent backups... once a day for work... once a week if it's home hobby work... Hopefully it's the power supply. If its not quite up to max wattage (dying) then the drives wouldn't spin up in the time limit. I've had that happen before. (more than once) It could be other things of course, but power supply and general hard drive failure is the most common.. unless there is some problem with some recent OSX update or something.
  6. mildewproductio thread starter macrumors newbie

    Dec 20, 2007
    Well it looks like we figured out the problem. Would you believe that a screw fell into the casing and caused a short between the two drives. When we pulled one of the drives out, the screw fell out. We plugged the drive back in and would you believe it the Mac sees it.

    We guess the screw caused a short, but who knows for sure.

    It works now though WOOT.
  7. termina3 macrumors 65816

    Jul 16, 2007
  8. California macrumors 68040


    Aug 21, 2004
    Hey mildew, hard drives are mechanical elements that wear out after three to five years max.

    REPLACE your raid drives. NOW. After you back up of course. HDs are cheap now.
  9. OrangeSVTguy macrumors 601


    Sep 16, 2007
    Northeastern Ohio
    yes you can buy 500gb sata hdds for less then $100 bucks! i'd like to buy 2 and use one for a mirror backup

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