4 Replies Latest reply: Feb 20, 2012 5:19 PM by X423424X
liquidmice Level 3 (750 points)

I recently attempted to create a disk image of an HFS+ Volume (my main OSX partition) using Disk Utility under 10.6.7. Used default config (compressed .DMG). Seemed to work fine until I attempted to "Restore" the .DMG to a new, empty partition. Received errors about no scan info being present, so I attempted to scan image for restore. Scan would not complete, received "internal error." After some research I decided to use terminal to force the restore without running the scan. Failure again, as the system could not mount the image. Attempting to access/mount the .DMG image via double-click also resulted in failure, "no mountable file systems." Are you kidding me? Eh well, maybe the .DMG got corrupted.


Finally, I gave up. The image was a compressed .DMG residing on an external drive (HFS+). I decided to do a complete re-install from DVD.


Upon re-install, I decided to attempt to image the Volume again, so I would have a base OSX .DMG for restore purposes. So now I'm back to 10.0, clean install. This time I created the .DMG on my desktop, thinking maybe the external was the culprit. Image created fine, but same problems experienced; would not scan for restore, would not mount. So I decided to try it again, this time without compression. Same game. Total failure.


It seems that Disk Utility isn't cut out for what I'm using it for. Or is my experience an anomaly? Anyone use 3rd party Mac utilities similar to Ghost or Acronis in the PC realm?

  • etresoft Level 7 (27,781 points)

    I don't think you can use Disk Utility to archive your startup volume while booted from that volume. I think Disk Utility uses a block-level copy and wants to unmount the volume before imaging. If it can't do that, it probably isn't going to work. If you boot from an install disk you should be able to create the DMG.


    The various clone tools (SuperDuper! and Carbon Copy Cloner) can clone a running system.

  • liquidmice Level 3 (750 points)

    As ridiculous as your answer is, it appears as though you are correct. Sorry but... how stupid is that? It completes the imaging without a single error, only to produce a corrupt image file? Are you kidding me? How long has Disk Utility been around? They couldn't program a message into it? Concerning a process it cannot successfully complete? I should've just used dd.


    Anyway, thanks for the correct reply.

  • therealdoug Level 1 (0 points)

    This solved my problem: doing a disk-level copy of the dmg file:




    I booted up in recovery mode (hold cmd+R when booting up) and ran the commands in the Terminal.

    I also had to unmount (umount command) the drive I was copying to (my only internal drive, /dev/disk0).


    I had created a dmg of my entire disk drive using Disk Utility. After reinstalling OSX, it wouldn't restore in Disk Utility with "no mountable file systems" and "internal error" errors. After almost giving up and assuming the dmg corrupt, I came across the above link.


    An hour or so later (128GB drive, 80GB dmg file), dd was complete and I rebooted back to my exact installation!

  • X423424X Level 6 (14,215 points)

    FWIW, I know for a fact that Carbon Copy Cloner couldn't care less about cloning your boot drive while using that boot drive.  It's quite forgiving about doing things like that.  And yes, the clone is still bootable.