Can not see resize option for mac partition on Disk Utility

Discussion in 'OS X Yosemite (10.10)' started by ragavbpl, Nov 10, 2014.

  1. ragavbpl macrumors newbie

    Joined:
    Apr 4, 2011
    #1
    Hi Apple Support Community

    I am a new MBP owner and proud one.. recently I had thought of installing Windows 10 via bootcamp.

    I kept my bootcamp drive size as just 30 Gb and thought it would be enough, but this isn't a case. I need to increase my partition now and what I have read from different source is that I need to reduce mac partition size and then from inside windows merge that unallocated spaced into windows partition.

    But my problem is I don't see a way to drag and reduce mac partition, following is my mac Yosemite screenshot:
    https://www.evernote.com/l/ACAQZecPW-JCEaeG8E3Q9eX9NPEzB2ccVv0

    Kindly help me to get more space for Bootcamp partition.
     
  2. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #2
    That is because Yosemite turned your drive into a core storage volume and those cannot be resized. Disconnect any other drives you have and run the command below in Terminal to turn off core storage then you should be able to manipulate the partition normally.

    Code:
    diskutil cs revert /
     
  3. ragavbpl thread starter macrumors newbie

    Joined:
    Apr 4, 2011
    #3
    Hi Weaselboy, thank you very much for the reply.. I ran this command and now I am able to see the resize option.

    Could you please try to explain this command and what was the problem and how running this command helped me? I am just curious to understand the process behind it.
     
  4. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #4
    Core strorage is Apple's storage technology that makes the disk(s) look like one logical volume to the OS. It is used, for example, on the newer Fusion drives. Nobody is exactly sure, but Apple is by default turning this core storage format on with newer Macs during the Yosemite installation. There is some speculation it related to an upcoming cloud storage integration.

    That command I gave you just "reverts" the core storage back to a normal disk volume.

    That diskutil command is documented here is you want to read more about it.
     

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