External Hard Drive Partition Question.

Discussion in 'Mac Basics and Help' started by zerocustom1989, Dec 28, 2008.

  1. zerocustom1989 macrumors regular

    Sep 5, 2007
    Hey guys i've got an external Hard drive with 45 gigs of free space left on it and i'd like to make 15Gb of that a separate Partition.

    Is this possible to do? If so, how?
  2. Techguy172 macrumors 68000

    Feb 2, 2007
    Ontario Canada
    Yep Just open Disk Utility and then plug in your hard drive select it and then click the Partition tab and go on from there.
  3. sickmacdoc macrumors 68020


    Jun 14, 2008
    New Hampshire
    Well as the previous poster said it will done in Disk Utility, but I think that answer needs to be expanded on a bit assuming you want to keep the data on your drive. If you are planning to back it all up to another external disk before repartitioning the disk, then disregard the info below and just reformat and partiton the drive! ;)

    First off, adding a partition to a drive with existing data without destroying the existing data (nondestructive partitioning) can only be done if:

    • Your OS is 10.5 Leopard
    • Your external drive was formatted for Mac use when it was empty (including both being formatted as Mas OS Extended (Journaled) and using a "GUID" partition map scheme), rather than leaving it formatted for PC use as most new external drives are when new.

    To double check the existing drive format status first, go into Disk Utility to check it. Click the drive to select it in the left column and look at the info at the bottom of the screen- particularly the "Partition Map Scheme:" entry. If it is listed as MBR (or Master Boot Record) then it is still formatted as a PC drive so nondestructive partitioning would not be possible.

    If it is formatted for Mac use, then the following information from Disk Utility's Help menu should guide you through adding a partition nondestructively:
  4. zerocustom1989 thread starter macrumors regular

    Sep 5, 2007
    Ah yea, I suppose I should provide some more information.

    I do want to attempt to keep the data and i don't have any other place to back it up to, lol.

    175Gb is a Time Machine Partition.
    The other bit is FAT32 format.

    It's this other bit that i want to divide into 2 pieces. The +- buttons in disk Utility are grayed out when I highlight the FAT32 portion though :-\

    Is it because it's a FAT32 format? I suppose a WindowsBeta test run can wait...
  5. allsecur3 macrumors newbie

    Dec 28, 2008
    If you have norton partition magic for mac, your life will be easier.

    I just dont know if there is "partition magic for mac" :)
    this tool is very good in creating partition to an active/loaded drive... it moves files seamlessly..
  6. sickmacdoc macrumors 68020


    Jun 14, 2008
    New Hampshire
    Ok, got you. You are right that Disk Utility will not do anything with a FAT32 partition unfortunately as far as resizing/splitting goes.

    One workaround for that would be to download the free Mac utility WinClone which is for backing up your Windows installation as a disk image. You could back up your Win installation, then blow away the FAT32 partition in Disk Utility then re-establish two partitions in the space freed up by doing that. Disk Utility can then be used to format those two partitions as FAT32, after which you could restore (using WinClone again) the disk image you made to one of the partitions, leaving the other ready to experiment on.

    Or you could shrink the Mac OS partition with Disk Utility then establish a new partition in the newly freed up space, then format that partition only as FAT32. From past experience that carries the problem of rendering the existing FAT32 partition non-bootable without some fairly heavy duty Windows repair routines though.

    On the other hand, probably a lot simpler to just wait 'til you have another drive to use to back up this one (since that would be highly recommended anyway) and set up the existing one from scratch using the instructions in several threads regarding triple boot disks! ;)

    BTW- Will the Windows 7 beta install on a FAT32 partition?

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