How to format a disk for use as a bootbable backup?

Discussion in 'Mac Basics and Help' started by GilesM, Sep 9, 2011.

  1. GilesM macrumors 6502

    Oct 17, 2008

    I am ready to migrate my iMac from Leopard to Snow Leopard.
    I have a copy of Carbon Copy Cloner and a spare drive with enough capacity to make a bootable clone of my Macintosh HD, prior to starting the upgrade.

    So, I started CCC and selected the Macintosh HD volume as a source, and selected the external hard drive as a destination.
    The External drive is formatted as "MAC OS Extended Journaled".

    As I went to start the clone process a window popped up telling me that I may not be able to boot from the Drive as some format's need to be applied.

    I tried the process again, and the warning no longer appeared. I cancelled the process as I wanted to be sure this drive will be bootable.

    Are there any actions I should take prior to starting CCC and letting the copy run? Is there any formatting I need to apply to the external drive?
  2. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    the partition scheme is what matters. you need GUID partition scheme. osx extended journaled is the way a specific partition of formatted.
  3. GilesM thread starter macrumors 6502

    Oct 17, 2008
    old wiz

    Well, I managed it the end, and have tested that the system can boot from the external drive. Thanks four your help.

    Now ready to upgrade... once the SL disk arrives...

Share This Page