Putting your ATV hard drive image on a CD

Discussion in 'Apple TV and Home Theater' started by Cave Man, Apr 8, 2008.

  1. Cave Man macrumors 604

    Cave Man

    Feb 12, 2007
    Neander Valley, Germany; just outside Duesseldorf
    I've figured out a way to compress a 40 gig ATV disk image down to 487.5 mb, small enough to fit on a CD. Here's what I did.

    1. Do a factory restore of the Apple TV. This deletes all the content on the hard drive. Unplug the ATV and pull its hard drive.

    2. Connect the hard drive to a Mac by any number of means. I use a universal drive adapter that connects the drive by USB. Two partitions should mount: OSBoot and Media.

    3. Launch Disk Utility. Click on the OSBoot partition and erase the free space using the one-pass zero write. This puts a zero on every unused byte of the partion. For OSBoot, it'll only take a couple of minutes. Next, do the same with Media partition. This will take about 30 minutes. At this point, all the unused bytes are now zeros.

    4. Use the dd command in terminal to image your ATV's disk to your computer's internal hard drive. You'll need 38 gigs of free space (or about 150 gigs if you have a 160 gig ATV drive). The directions for this can be found here. A 40 gig drive takes about 2 hours by USB. A bit faster if it's Firewire.

    5. Use Archive.app (right-click on the image icon and choose "Compress...") to compress the ATV drive image. Since you made all of the unused space on the hard drive zeros, Archive.app will be able to zip it more than 98% (37.26 gb down to 487.5 mb). This took about 2 hours on my 1.66 core duo mini.

    6. When you need it, simply unzip it (make sure you have 40 gigs of hard drive space available!). It took about half an hour to unzip on my machine. Just let it run.

    7. You can now use dd to put it back to a hard drive. If you put it on a drive larger than 40 gigs, you can use iPartition to increase Media's size to the hard drive you put the image on.

    This will also work with a 160 gig ATV, but it'll take longer to zero the Media partition, read the drive for imaging, and to compress/decompress it. However, I suspect you could still put the compressed image on a CD.
  2. tom1971 macrumors 6502a

    May 15, 2007
    Hi Caveman,

    what is it good for?
    Whenever you do a factory restore, you get the original file structure, don't you?


  3. iFizz macrumors regular

    Apr 2, 2008
    Third planet from the star called "Sun"
    If one were to do any hacking of the ATV HD (i.e. replace with faster/larger and/or external HD), one would want a backup of the original HD image.
  4. abrooks macrumors 6502a

    Sep 18, 2004
    London, UK
    Anyone willing to supply the image? Could you PM me?
  5. Cave Man thread starter macrumors 604

    Cave Man

    Feb 12, 2007
    Neander Valley, Germany; just outside Duesseldorf
    I've updated the first post to reflect the use of Archive.app in OS X. It is essential that you zero the drive before imaging it, otherwise Archive.app will fail to zip the image.
  6. barnettworks macrumors newbie

    Feb 18, 2010

    Hey Cave Man! Nice work on this!! I zapped my HD this morning when I was tinkering around with the cooling issue you were talking about, can you ftp this base CD image you made? Of course since I had recently bought mine I had never made a backup of my image! Dooop! anyways if you can that would be awesome. I have a ftp server up and running if you can do this.

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