Add space to partition without deleting data

Discussion in 'macOS' started by lenntheox, Mar 7, 2013.

  1. lenntheox macrumors newbie

    Mar 7, 2013
    First time poster, long time reader. You guys have really helped with my problems from since I can remember. But now I've make the plunge to join up since I have a little predicament.

    In trying to fix a bootcamp problem on my iMac running Lion, I have a 150gb partition which I want to put back with my original partition. To my knowledge I have to reformat the whole drive to do that. Is there any way I can get around it without destroying everything?

    Thanks in advance
  2. w0lf macrumors 65816


    Feb 16, 2013
    If I'm understanding you correctly you want to erase your windows partition and restore your mac partition to it's original size?

    If that is the case then yes you can expand Mac OS Extended partition into empty space on a drive without reformatting the whole drive.

    As far as I'm aware you can not merge the two partitions together so if you care about what's stored on your windows partition I would recommend backing up anything you think is important onto an external drive or onto the mac partition if there is space.

    To remove your windows partition and expand your mac partition first open disk utility then follow these steps:

    1) Select your drive
    2) Click the partition tab
    3) Select your windows partition
    4) Click the minus button to remove the partition
    5) A dialogue box will ask you to confirm, select remove
    6) Once the windows partition has been removed simply grab the lower right corner of your mac partition and drag it into the now empty space
    6) Click apply
    7) Another dialogue box should appear, confirm and your mac partition will be resized
  3. lenntheox thread starter macrumors newbie

    Mar 7, 2013
    Ok, I followed the steps that you said and it came up with a dialogue box saying "Partition failed with the error: Couldn't modify partition map because file system verification failed"

    I'd better give some more context. A few days ago I needed to have windows running through boot camp again. After trying using the boot camp assistant it kept failing on me and not working for reasons I couldn't work out. In protest I looked up some ways to get around boot camp. The one I found was repartitioning the hard drive yourself using a special live cd Linux distro called gparted. After doing this, I repartitioned he hard drive and then booted into windows. This went along smoothly until it came up with a similar sort of message about the "partition map" being wrong. So I then booted back into lion where I had the problem which I have now.

    I also tried to go back into gparted to remove the partition, and it worked. I then went back into disk utility on the mac to resize and it came up with the same error.

    So thats the situation now, I hope that makes sense. I appreciate the help, and thanks again :)
  4. Kirk264 macrumors newbie

    Apr 27, 2014
    Easily back up all important partition data, delete these useless partitions in Disk Management and extend the unallocated space to your assigned partition there.
    But, if the Disk Management tool cannot help you out, you can directly take chances with some partition resizing tools, like GParted, IM-Magic Partition Resizer Free and Paragon Master Partition, etc.
    No matter what happens, always remember to back up your important partition data.
  5. Erica435 macrumors newbie

    Apr 28, 2014
    If your wanted files have not been overwritten yet, you may take chances with this video tutorial:
    It may also give you some help.
    Always remember to make data backups before the expanding process in case of data loss.
  6. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    I thought that once you bootcamp a drive, you need to use bootcamp to undo the process and return the space?

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