No RAID option in Disk Utility for new disks

Discussion in 'Mac Pro' started by Xzag, Nov 30, 2014.

  1. Xzag macrumors member

    Mar 19, 2012
    I inserted 4 new 3TB disks into the bays of my Mac Pro (2012), and there is no RAID option for them.

    How I got here:

    Inserted the WD Red drives, and they were not initiated.

    I "erased" the drives, gave them names, and they appear in Disk Utility in grey drives.

    Went to set up the RAID, and move the drives into the RAID, but got an error that they could not be used.

    It appears to me that disk utility is not allowing me to fully use those drives. I Have created RAID drives before with no issue in RAID1 with 3TB drives before on this machine. Am perplexed, I thought this to be the easy and simple part of my upgrade odyssey! Did I screw up the initialization? On all FOUR drives?

    Now, if I click on the drives, the RAID option does not present itself.

    FWIW, I am using OS X 10.9.5, on Mac Pro 5,1. I boot from PCIe card. My end goal is to create a 4-disk RAID 10 using the four SATA connections on the MP.
  2. Xzag thread starter macrumors member

    Mar 19, 2012
    FWIW, here is what my disk utility GUI looks like

    Attached Files:

  3. Draeconis macrumors 6502a

    May 6, 2008
    You can only do software RAID0 and RAID1 in OS X normally. For anything more advanced, I'd check out OpenZFS :)
  4. ssls6 macrumors 6502a


    Feb 7, 2013
    The drives have been converted into core storage volumes already. You need to make them standard format first.

    Either try again to create standard formats or use the diskutil cs revert command.
  5. Xzag thread starter macrumors member

    Mar 19, 2012

    From another forum, and this worked:
    here is a known BUG in 10.8.4 and later for drives over 2.2TB ERASEd in the internal bays. It creates a Core Storage Group for them instead of a simple Volume, and they are then useless.

    Work-arounds include:

    • Erase again in an external enclosure (one modern enough to actually erase a >2.2TG Drive)
    • Erase with an older version of Mac OS X, such as 10.6 off the "Full Retail" DVD if you Mac can boot from it [Mac Pro 5,1 requires custom 10.6.4 minimum] or your original "shipped in the box" DVD, if available.

    NB> one user who simply used "Partition" instead of ERASE escaped this issue entirely.

    Thanks everyone. Disappointing that Apple left such a large hole....I took the drives out, re"erased" them, put them back in to the MP, and was able to create the RAID. Now to spend some quality time on moving data.

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5 November 30, 2014