Resolved (SOLVED!) Possible to resize multiple partitions on flash drive?

Discussion in 'Mac Basics and Help' started by Diogones, Apr 1, 2016.

  1. Diogones macrumors regular


    Dec 23, 2009
    Hey all,

    I have a 2008 24" iMac running El Capitan 10.11.4. I have a USB flash drive that I keep for diagnostic and troubleshooting purposes. It is formatted HFS+ with the GPT partition scheme. I have 6 partitions on the drive: 5 of them are bootable OSX installers for the most recent OS X versions, and the 6th one is a diagnostic partition that is a bootable El Capitan system with various troubleshooting software on it, such as DiskWarrior, Data Rescue, etc. I've enclosed screenshots of the drive in Disk Utility and the Terminal output from the diskutil -ls command for reference.

    My question is this: I would like to be able to enlarge my Diagnostics partition by shrinking one or more of the other partitions, which have some free space. Is this possible? And can I do it non-destructively? It seems like the only way to make it work is to delete one or more of the partitions in order to reclaim the newly freed space, and then remake the partition.

    I wasn't able to resize the partitions in Disk Utility (DU) initially. I converted a couple of the partitions to CoreStorage, and then I was able to actively resize them in DU. I'm not worried of having to do Terminal commands to get the job done, or even using a third party partition tool, such as iPartition.

    Any helpful advice would be greatly appreciated!

    Disk Utility.jpg Terminal.jpg
  2. chown33 macrumors 604

    Aug 9, 2009
    The basic rule about partitions is you can grow or shrink them as free space allows, but you can't move their starting point.

    Since growing the Diagnostic partition would require moving its starting point downward into free space gained by shrinking the "El Capitan" partition, the answer is "You can't do that".

    See here for explanation of how a partition is represented:
  3. Mcmeowmers macrumors 6502

    Jun 1, 2015
    This is a complicated task - you could try gparted.

    Otherwise the manual way would be-
    If you want to remove all of the free space and move all partitions to the front of the drive you're going to have to delete them all.

    shrink the first one,
    copy the second to another location - delete the original second partition,
    copy the new second back to the drive after adding a new partition,
    copy the third to another location....

    Or maybe CCC could help with this too
  4. Fishrrman macrumors P6


    Feb 20, 2009
    Get a SECOND flash drive and "spread out" the partitions/tasks between them.

    Seriously -- it will probably be much easier!
  5. Diogones thread starter macrumors regular


    Dec 23, 2009
    Thanks all for your prompt and helpful replies!

    I've decided on two things:

    First, as chown33, Mcmeowmers, and Fishrrman have pointed out, it either isn't possible to do what I'm attempting, or it is very difficult to accomplish. So I may have to follow Mcmewowmers advice and delete all the partitions.

    Thanks to some recent research I did, I've discovered that I will need to redownload and recreate the OS X Installer partitions anyway, due to the Apple Worldwide Developer Certificate expiring on February 14 of this year:

    I could use the workaround suggested in that article, which is to just use Terminal to change the system date, but I'd rather opt for the permanent solution.

    The second decision I've reached is what Fishrrman suggested, and that is to get a second flash drive. Even after I delete the OS X Installer partitions and resize them to give me a little bit more free space, I hardly have any left on my Diagnostic partition anyway. This is causing the system to boot much slower than if I had more free area available for the OS X system on the partition to work with. So I think I'll use this 64GB for my Diagnostics rescue thumb drive, and get a second large thumb drive for the OS X Installers, with room to grow as more OS X versions are released.

    Thank you again for everyone's advice! I'm marking the thread as solved.

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4 April 1, 2016