Partitioning an External Drive without Erasing

Discussion in 'OS X' started by xXriderXx7, Nov 3, 2007.

  1. macrumors 6502a


    Jul 6, 2007
    Lake Elsinore, California
    In the effort to use Time Machine, I want to partition my external drive.
    I have 500 gig external, and would like to have one partition of 480 and one around 20. This way, Time Machine will only back up onto the smaller partition, not endlessly backing up until all 500 gigs are used.

    The reason I need to partition without erasing is my 170 gig iTunes library. Its too large to transfer to my internal HD, and I have no other drive to store it on.

    Anybody have any ideas?
  2. macrumors 68000

    Jan 27, 2007
    Leopard Disk Utility allows dynamic partition sizing, but I'm not sure if you can do that with existing partitions or just partitions created with you partitioned and formatted the disk with leopard.

    Plug in the drive and open disk utility to see if the partitions are resizable. Nothing will happen until you hit the "accept" button, so don't worry.
  3. thread starter macrumors 6502a


    Jul 6, 2007
    Lake Elsinore, California
    No go.
    All data will be erased.

    Ive heard Drive Genius can repartition without erasing.
    Is this true?
  4. macrumors 603


    Oct 29, 2006
    ~119W 34N
    Did you try making it 2 partitions or drag the current one to resize? If the former, it will want to erase and create 2 new ones.

    Try grabbing the "bottom" of the current partition and slide it up to create some free space. It should be able to do this on-the-fly (no erasing). Then, you can create a new partition in the free space.

    Important: you shouldn't do any modifications to partitions without a backup.

    edit: you might be thinking of iPartition. It's not Leopard compatible, yet, but it sounds like it will be soon. It can resize, create/delete and move partitions on-the-fly.
  5. thread starter macrumors 6502a


    Jul 6, 2007
    Lake Elsinore, California
    I didnt even notice the resize dragger. Successfully backing up to my new partition.
  6. macrumors 6502


    Jul 2, 2006
    East Asia
    I was pleasantly surprised to find that the partitions I had made on my external HD with Tiger, were easily adjustable once I installed Leopard. Totally sweet to be able to resize partitions on the fly!
  7. aoe
    macrumors newbie

    Oct 7, 2007
    It should be noted that you can't resize external fat 32 partitions. I have my external 500gb partitioned as 1 big fat 32 so I can access it in windows. I wanted to half it up to hfs so I could store my hd movies (>4gb) but I couldn't.
  8. macrumors 68020

    May 15, 2005
    change the size?

    IS there a way to change the size of two partitions?

    I have a 200MB partition for storage and a 300GB partition for TM. I would rather have the 200 for TM or LESS and the 300GB for storage or more?

    In the disk utility, I can certainly grab the corner of the 300GB TM partition and shorten it, but then WHAT happens to the freed up space? Can I ADD it to the 200MB partition?

    IS there a way to do this?
  9. macrumors 6502

    Sep 15, 2007
    i also would like to know this answer
  10. macrumors member

    Nov 15, 2007
    I am getting ready to partition a drive that I cannot erase so I can limit the build-up of time machine on it.

    Can someone explain to me how to use "resize image" to do this? I've never done it before.

    The external drive is 320 GB, with 60 used. My Powerbook has 40 GB free. (So I can't just 'float' it.)

    I know you can limit what time machine backs up file-wise, but I would like to limit its capacity so I do not get surprised when my external is suddenly full.

    EDIT - Nevermind, it works if you just trust leopard and tell it to partition.
  11. macrumors newbie

    Nov 29, 2007
    I also have a question that I think relates to this thread.

    I have an external, 500 GB drive with data on it (but only using about 20 gb) from my old windows computer. The drive is formatted as FAT32, and has no partitions. I was wondering if I could get Leopard to create a partition with the mac format for time machine to use, but it seems from the above posts that I can't. I might just let time machine reformat the whole ext. drive, but can I first move the files (eg: word docs, photos, misc. junk) into my macbook's drive, and then later drag them back to the ext. drive? Or would that be unnecessary, since time machine will be backing up everything on my macbook's drive?

    I'm a bit unclear if time machine creates a full drive image (I used to use acronis true image on my windows laptop to create backups)?
  12. macrumors newbie


    Feb 11, 2008
    Partitioning and Keep FAT32

    so i was wondering, i want to partition my external 500GB HD for TM through leopard but since its formated in FAT32 all it will do is erase the whole HD and then partition it. is there a way i can keep the FAT32 part and create an OSX part that i can use for TM?
  13. macrumors 65832


    Jan 13, 2008
    sorry if this is an old post but i can answer it.
    i was just wondering also these questions.

    open disk utility
    click on the main drive on the left side and go to partition
    look at the rectangle in the middle of the page that shows your drive and how the space is allocated.

    in the bottom right hand of that box there is a little ripple (do not know what you would call it) but you can move that up and down, once you do that click the plus button under it and a new partition will come up.

    im not 100% sure this works
    as im doing it right now.

    but it does say, on the right of that box and in the dialog box when you click apply it says
    drive å will not be erased
    drive ß will be created.

    well lets hope this works as i have a 70+ gb itunes library i would hate to loose.

  14. macrumors 6502a


    Jan 28, 2007
    New Jersey
    so here's another similar question...

    I have a 1TB drive already partitioned into 2 partitions. One partition is about 600GB for TM and the other one is about 300GB for storage.

    I would like to take some space away from the TM partition and give it to the storage partition. I see the dragging "grips" on the partitions graph, but I can only drag over free space to create a third partition... I can't seem to find a way to give space from one partition to another.
  15. macrumors 65832


    Jan 13, 2008
    actually i have no clue, now i want to find this out.
    damm and i actually kinda need to do this, only 10gb left for time machine
  16. macrumors newbie

    Sep 28, 2008
    I am trying to partition my external hard drive without erasing it. However, I don't see those ripples in the bottom left hand of the rectangle. Here is a screen shot:

  17. macrumors 68040


    Apr 8, 2004
    See the Volume Scheme: "current" option? Select that and then "2 partitions" (or however many you want).
  18. macrumors newbie

    Sep 28, 2008
    I will have to erase my Hard drive then. Right? I'm trying to partition my hard drive without removing all the data.
  19. macrumors regular

    Jul 24, 2008
    I am also trying to do this, the wd is formatted as FAT32. Is there a way for me to take 200Gb of that, and format as hfs, and yet be sure, the other files are still intact? I also have a windows computer with which i use the hd
  20. macrumors member

    Aug 8, 2007
  21. macrumors 68020


    Jun 14, 2008
    New Hampshire
    Short version of the answer is no you cannot since your disk has a Master Boot Record partition scheme.

    See the Partition Map Scheme (where it reads Master Boot Record) at the bottom of the screen?

    That is why you cannot resize partitions in Disk Utility without erasing on this disk. MBR is the partition scheme for a hard drive prepared exclusively for Windows. To prepare a new drive for MacOS, the first step should be to go into the Partition tab- then you must change the "Format Scheme" at the top to 1 (or more) instead of "current" as it will read by default. Changing that will cause the "Options" button at the bottom to become black, hence selectable.

    Click on the Options tab, and select from either the Apple Partition Map (for PowerPC based Macs or GUID Partition Table (for Intel based Macs), not Master Boot Record for Windows.

    Once that is selected, choose Mac OS Extended (Journaled) for the "Format" at the top of the screen, give the drive a name and click either "Partition" or "Apply" (whichever appears at the bottom right of the screen). Wait a few seconds and you will have a disk that is capable of having partitions resized, added and subtracted without data loss.

    Disk Utility is simply not capable of anything but basic erasing (formatting) on a disk with a partition type of Master Boot Record.

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