6 Replies Latest reply: Feb 14, 2013 9:21 PM by mende1
Cunnla Level 2 Level 2 (205 points)

Hi, I have a USB hdd that was used for TV recording but failed on that so I reformatted it as Mac OS extended journaled with 6 partitions (GUID), and using SuperDuper, cloned Lion from a Macbook Air and Tiger from my eMac into different partitions, with the idea of using it as an extra backup.

Tested the USB drive on Disk Utility verify disk function and it said all 6 partitions appear OK. Can boot the MBA from the USB drive (although slow) but the eMac does not show the disk image on the USB drive as an optional restart item.  I have eMac backed up on a separate Firewire drive but would like to use the USB drive as a second line of defense.

My question is, would I be able to restore from the Tiger dmg on the USB drive, given that it is GUID and not Apple partition scheme. Would I have to reformat it to Apple partition scheme. Also, how would you go about a restore  from the USB drive if the eMac's OS was kaput?


MacBook Air, Mac OS X (10.7.5), eMac and Mini on OS X 10.4.11
  • 1. Re: Can I use same USB drive for Intel and PPC backup?
    mende1 Level 10 Level 10 (89,570 points)

    You can't store a clone of an Intel-based Mac and a clone of a PowerPC-based Mac on the same drive.

     

    That's because an Intel-based Mac can start from a GUID partition table, but a PowerPC-based Mac can only start if your USB drive is using Apple Partition Map instead of GUID. In your case, you have to buy another external drive to make a clone of the PowerPC-based Mac or the Intel-based Mac.

     

    To change the partition map of your USB drive:

     

    1. Open Disk Utility (it's in Applications > Utilities folder), and select your USB drive in the sidebar.

     

    2. Go to Partition tab, and press "Options" button, where you can choose the partition map you want: GUID, MBR or Apple Partition Map. Note that you won't be able to start an Intel-based Mac from a drive that uses Apple Partition Map

  • 2. Re: Can I use same USB drive for Intel and PPC backup?
    Cunnla Level 2 Level 2 (205 points)

    Thanks for the response. Now I know it has to be one or the other.

    So if I have a USB hdd with Apple Partition Map and the OS X 10.4.11 disk image on it, will the eMac recognize the disk image as an alternative boot?

    Regards

  • 3. Re: Can I use same USB drive for Intel and PPC backup?
    mende1 Level 10 Level 10 (89,570 points)

    Cunnla wrote:

     

    So if I have a USB hdd with Apple Partition Map and the OS X 10.4.11 disk image on it, will the eMac recognize the disk image as an alternative boot?

     

    Correct

  • 4. Re: Can I use same USB drive for Intel and PPC backup?
    rccharles Level 5 Level 5 (5,370 points)

    With the exception of a few G5 machines, no one has reported success with booting from a USB external hd on a PPC.

     

    You can save your data on the USB drive.

     

    Robert

  • 5. Re: Can I use same USB drive for Intel and PPC backup?
    Cunnla Level 2 Level 2 (205 points)

    Thanks all for the advice. So it seems there's not much point in having a bootable clone on a USB hd as far as PPC is concerned. If you cannot boot from it you cannot do a reverse clone.

    I'll use this USB drive for the Intel backup and media storage and the firewire one for the eMac and Mac Mini.

    BTW, gave myself a star by mistake, is there a way to remove it?

    Regards

  • 6. Re: Can I use same USB drive for Intel and PPC backup?
    mende1 Level 10 Level 10 (89,570 points)

    Unfortunately, it's not possible to remove it. You are welcome