Recovering a partition on Fusion Drive without losing data

Discussion in 'iMac' started by imacken, Mar 14, 2018.

  1. imacken macrumors 65816

    Feb 28, 2010
    I have a 500Gb partition on my iMac that I want to put back into the main Fusion drive.
    How can I do this WITHOUT a wipe and reinstall?
  2. Fishrrman, Mar 14, 2018
    Last edited: Mar 14, 2018

    Fishrrman macrumors P6


    Feb 20, 2009
    Can you delete it using Disk Utility?
    I would not attempt this UNLESS you have a just-done backup of your main partition.

    IF DU won't do it, my standard recommendation:
    1. Use a cloning app (CarbonCopyCloner or SuperDuper) to clone the contents of your main partition to an external drive, creating a BOOTABLE backup.
    2. BOOT FROM the cloned backup
    3. Open Disk Utility and ERASE the internal fusion drive. Set it up with one partition only.
    4. Now re-open your cloning app and RE-clone the backup BACK TO the internal drive.

    This will take some time, but it -WILL- "do the job" properly.
  3. imacken thread starter macrumors 65816

    Feb 28, 2010
    Thanks. I was trying to avoid all that. Don’t really understand why DU can’t do this (apparently) simple task.
  4. nambuccaheadsau macrumors 68000


    Oct 19, 2007
    Nambucca Heads Australia
    Recovering partition space is never simple.

    This 500GB partition ~ is it actually on the platter hard drive? If so follow the fisho's suggestion. It is quite simple if a little time consuming.
  5. imacken thread starter macrumors 65816

    Feb 28, 2010
    Thanks for your help guys. I know how to do it from scratch, but I really wanted to avoid doing all that.
    Oh well.....
  6. BLUEDOG314 macrumors 6502


    Dec 12, 2015
    Can you run 'diskutil cs list' in terminal and post what you get here please. I am not understanding your questions or how the partitions are laid out and would need that to help you.
  7. imacken thread starter macrumors 65816

    Feb 28, 2010
    See attached. I have a Fusion Drive of MacintoshHD (1.5Tb HDD + 121Gb SSD) plus a partition called Temp of approximately 500Gb. I just want to get my Fusion Drive back to 2Tb by bringing the 500gb back into Core Storage without reformatting/reinstalling etc. sg.jpeg sg2.jpeg
  8. imacken thread starter macrumors 65816

    Feb 28, 2010
    I've sorted it out. DU worked ok when booting from my CCC clone. All good now. Thanks for your help.
  9. vkd macrumors 6502a


    Sep 10, 2012
    So did you manage to add the 500GB partition to the Fusion Drive? I would be interested to know how you did it because I too have a FD and understood that once created they are fixed in size and can't be altered.
  10. Bigdog9586 macrumors 6502

    Apr 15, 2015
    Funny how I’ve deleted my bootcamp partition twice now without losing any data from the Mac side.
  11. imacken thread starter macrumors 65816

    Feb 28, 2010
    Sorry about late reply.
    I did it by using DU from a bootable CCC clone, and yes, the 500Gb was added to the FD. DU wouldn't do it when I was booted in the FD itself. It just crashed!
    So, all good.
    --- Post Merged, Mar 17, 2018 ---
    Good for you. I wasn't asking about deleting the Bootcamp partition, I was asking about reclaiming the 500Gb back into the FD.

Share This Page

10 March 14, 2018