Ambrose McNibble

Q: How Do I Manually Rebuild OSX Software RAID?

I have a "Degraded" RAID mirror set as part of a 4-disk software RAID 10 Array. The instructions here:

How to rebuild a software RAID mirror - Apple Support

say to click "Rebuild". There no "Rebuild" to click in Disk Utility 13. (See screen shot)


How do I rebuild my RAID?

 

Thank you.

 

no_raid_rebuild_button-1.jpg

Mac Pro (Early 2009), OS X Mountain Lion (10.8.5)

Posted on Jun 19, 2015 5:32 PM

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Q: How Do I Manually Rebuild OSX Software RAID?

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  • by Kappy,

    Kappy Kappy Jun 19, 2015 5:44 PM in response to Ambrose McNibble
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    Desktops
    Jun 19, 2015 5:44 PM in response to Ambrose McNibble

    The rebuild is an option that must have been checked at the time the mirror RAID was created. Since it doesn't happen by default your RAID cannot be rebuilt. Your option at this point is to break the RAID. This will leave you with two drives containing the exact same content. Unfortunately, to create a new mirror RAID means you must erase the content of both drives. I suspect that isn't an acceptable option.

     

    There is a third-party RAID software utility, SoftRAID 5.0.7, but it's pretty expensive. And, I have no idea if it would fix yours.

  • by Ambrose McNibble,

    Ambrose McNibble Ambrose McNibble Jun 20, 2015 4:29 PM in response to Kappy
    Level 1 (0 points)
    Jun 20, 2015 4:29 PM in response to Kappy

    The link I reference says I can rebuild manually even if I don't select the auto rebuild option when I create the RAID.

     

    Are you saying the Apple documentation is wrong about how their RAID software works?

  • by Kappy,

    Kappy Kappy Jun 20, 2015 4:48 PM in response to Ambrose McNibble
    Level 10 (271,057 points)
    Desktops
    Jun 20, 2015 4:48 PM in response to Ambrose McNibble

    No, I'm not saying that. I don't know if it's wrong. The documentation states:

     

    If you did not enable the "RAID Mirror AutoRebuild" option in the RAID options dialog when you created the RAID, you need to rebuild the disk yourself. To rebuild a disk in a mirrored RAID set:

    1. Open Disk Utility.
    2. Select the RAID set, and then click RAID.
    3. Click Rebuild.

     

    The above is what you need to do. You haven't selected the RAID set in Disk Utility.

  • by Ambrose McNibble,

    Ambrose McNibble Ambrose McNibble Jun 20, 2015 6:23 PM in response to Kappy
    Level 1 (0 points)
    Jun 20, 2015 6:23 PM in response to Kappy

    As the screen-shot shows, I have selected the RAID set in Disk Utility. I have completed steps 1 and 2 at the point of that screen shot. I've also tried selecting everything and anything else looking for some magic combination to make "Rebuild" appear.

     

    Are you sure you know how this software works? Or are you just guessing trying to get points?