Can't remove a deleted partition

Discussion in 'OS X Mountain Lion (10.8)' started by jswl, Feb 3, 2014.

  1. jswl macrumors newbie

    Joined:
    Feb 3, 2014
    #1
    I have a 2TB external hard drive with two partitions that I want to not be partitioned. I removed the 2nd partition and expanded the first one to the total space of 2TB. However, in disk utility, the top tier of the 2nd partition still appears listed but when I connect the drive I get an error message reading "The disk you inserted was not readable by this computer."

    So, how can I get that 2nd partition to be totally removed and not listed, with the drive reformatted to be just one big 2TB drive with no partitions?

    Thanks!
     
  2. Weaselboy Moderator

    Weaselboy

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    California
    #2
    I assume here there is no data you need on the drive.

    Attach the drive and start Disk Utility and go to the erase tab. Then select the drive name itself (like Seagate 1TB or whatever) and name the drive to the right side. Then select Mac OS Extended as the format the apply. This will wipe the whole drive to one partition with whatever name you supply.
     
  3. jswl thread starter macrumors newbie

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    Feb 3, 2014
    #3
    I wish it would work that way for me. It shows as two separate drives in disk utility, even after I erased both of the partitions. I can't select just one main drive with both partitions. I can select both of them together but then the options are grayed out. The empty one still shows and still tries to mount. When I try to verify or repair the error message shows partition map fail because no slices were found.
     
  4. Weaselboy Moderator

    Weaselboy

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    #4
    It still sounds like you are trying to use the partitions section of Disk Util.

    I am talking about the erase tab below. I made two partitions on a USB key here in the partitions section, then switched over to the erase tab and selected the drive name at the top (16.24GB Corsair in my screenshot.

    [​IMG]

    Then I just click erase at the lower right there and I get back to one partition. Is this what you tried?

    [​IMG]
     
  5. jswl thread starter macrumors newbie

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    Feb 3, 2014
    #5
    Yes, I did erase, but I am still left with two separate 2TB drives named the same, rather than 1 big 4TB drive.

    [​IMG]

    And I can remove (by using the minus sign) the second partition, which removes the 2nd untitled, but cannot make one 4TB partition.

    [​IMG]
     

    Attached Files:

  6. b0fh666 macrumors 6502a

    b0fh666

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    #6
    do you have CoreStorage on that disk (encryption)? wiping such a disk is trickyer.
     
  7. Weaselboy Moderator

    Weaselboy

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    #7
    This is odd. Your first post mentioned one 2TB drive, but you are now saying you have only one 4TB drive attached there and that is the only external attached?

    Go to Terminal and enter the command below then post the output.

    Code:
    diskutil list
    Then do the same with this command and post the output.

    Code:
    diskutil cs list
     
  8. DeltaMac macrumors 604

    DeltaMac

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    Location:
    Delaware
    #8
    The model number for your drives (HDS723020BLA642) are all for the same 2 TB drives.
    So, it looks like you have an external case that has two 2 TB drives…
    Total storage is 4 TB, to be sure - but not on a single volume without using some kind of RAID or core storage setup.
     
  9. jswl thread starter macrumors newbie

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    Feb 3, 2014
    #9
    Yes, I did originally say 2TB, and I was wrong... it's a 4TB with 2 2TB partitions. The first on the list is my internal hard drive.
    I obviously don't know a lot about drives, so I don't know what they are all named the same. but I did not set up RAID or core storage on this one.

    Here is the info from Terminal:

    diskutil list
    /dev/disk0
    #: TYPE NAME SIZE IDENTIFIER
    0: GUID_partition_scheme *2.0 TB disk0
    1: EFI 209.7 MB disk0s1
    2: Apple_HFS Macintosh HD 2.0 TB disk0s2
    3: Apple_Boot Recovery HD 650.0 MB disk0s3
    /dev/disk1
    #: TYPE NAME SIZE IDENTIFIER
    0: GUID_partition_scheme *2.0 TB disk1
    1: EFI 209.7 MB disk1s1
    2: Apple_HFS Untitled 2.0 TB disk1s2
    /dev/disk2
    #: TYPE NAME SIZE IDENTIFIER
    0: GUID_partition_scheme *2.0 TB disk2
    1: EFI 209.7 MB disk2s1


    diskutil cs list
    No CoreStorage logical volume groups found


    Thanks!
     
  10. Weaselboy Moderator

    Weaselboy

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    #10
    This and Disk Util looks like two, physical 2TB drives to me. Can you explain what kind of enclosure you have and how this is all setup?
     
  11. jswl thread starter macrumors newbie

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    Feb 3, 2014
    #11
    It's one big unit, 4TB G RAID, connected with one thunderbolt cable, but the RAID was never set up.
    It was erased immediately out of the box and set up with 2 partitions.

    It's confusing because it does look like two separate drives.
    We have another that was setup with one partition out of the box and it behaves like one 4TB drive.
     
  12. DeltaMac, Feb 4, 2014
    Last edited: Feb 4, 2014

    DeltaMac macrumors 604

    DeltaMac

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    Delaware
    #12
    Not too confusing.
    It appears as two separate drives, because there are two separate drives inside the enclosure. When you reformatted the drive before using it, you reset the RAID setup that it shipped with. From the G-RAID web page:
    but, physically, it's two separate drives.
    from another G-RAID support page:
    So, it came set as a RAID out of the box, and you didn't need to make any changes at all.
    I'm not sure how you could have simply erased the RAIDed drives so that the two drives are usable independently?
     
  13. Weaselboy Moderator

    Weaselboy

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    #13
    Like DeltaMac said, it was already setup as RAID 0 and you undid it. You should be able to follow the RAID 0 instructions here and use Disk Util to set it back up as RAID.
     
  14. jswl thread starter macrumors newbie

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    Feb 3, 2014

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