Format Startup Disk without Installion CD

Discussion in 'Mac Basics and Help' started by Trueskool, Jul 6, 2008.

  1. Trueskool macrumors newbie

    Jun 5, 2008
    Hey guys,

    I'm currently out of town and don't have access to my Mac OS X installation disc and of course I've run into a bit of rough road recently which has lead to me needing to format my startup disk, zeroing out all data.

    I partitioned my 500G Western Digital and made a fully bootable backup of my disk using SuperDuper!. I booted from the drive and it works completely fine "I'm using it now". I proceeded to open disk utility needing to format the internal disk with the zeroing out data security option. I set the format to Mac OS X (Journaled), gave it the same name as before, and clicked erase. It prompted me with an error stating "Cannot erase because the drive could not be unmounted". So I attempted to unmount the drive and it prompted me with another error stating "Could not unmount the drive because it is in use... please close all applications...etc., which didn't work".

    After doing a bit of research I've read that to erase your hard drive you need to use your installation disc and follow the instructions, etc, etc.

    Now, as previously stated I don't have access to my Leopard disc so that's not an option, at least for another 3 weeks, when I return home.

    So my question is: Is it possible to format/erase your startup disk "My internal drive" without the use of your OS installation disc, and if so how would one go about doing it?

    Thanks in advance.

    Kind Regards,
  2. MisterEd macrumors 6502

    Jan 2, 2006
    The problem is that you need to be running the formatting program from something other than the hard disk you want to format.

    What I'd do: Download gparted and make a bootable disk with it. Start up with the disc in and hold ALT and choose to boot from the CD. Then from within the gparted app you will be able to reformat the disk. Obviously you won't be able to reinstall anything without the leopard disk...

  3. Trueskool thread starter macrumors newbie

    Jun 5, 2008
    I am running running disk utility from my my external's bootable backup I made. The hard drive i'm trying to format is located inside my computer. Anyways, I believe I got it working.

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