7 Replies Latest reply: Dec 21, 2012 3:30 PM by babowa
Smphoto74 Level 1 (5 points)

Got a new 2012 27" iMac and I can't get it to boot to my Thunderbolt Drive.  I can use my 2011 iMac and 2011 MBP and it boots to the Thunderbolt Drive just fine.   Thunderbolt drive is a Little Big Disk SSD drive.

 

After start up I get a chime, white screen then a cycle with a line through it then about 30 seconds later the iMac turns off.  Any Ideas?

  • varjak paw Level 10 (169,822 points)

    Did you install the version of OS X that came with your 2012 iMac on the exernal drive via the Recovery Partition on the iMac, or clone the iMac's hard drive via a tool like Carbon Copy Cloner? The late 2012 iMacs have a special build of 10.8 and won't boot from the version currently available from the App Store or on any earlier-model Mac.

     

    Regards.

  • Smphoto74 Level 1 (5 points)

    No I did not. :/  How do I get one now?  lol  I have tons of backups on different drives but had no idea about the 2012 iMacs having a speical version of the OS. 

  • varjak paw Level 10 (169,822 points)

    Boot your iMac from the Recovery Partition by restarting and holding down the Option key. You can then install that version of OS X on the external drive as normal and it should then work. Your iMac will need to have a working Internet connection for the installation.

     

    Regards.

  • Smphoto74 Level 1 (5 points)

    That's what I was afraid of...8 hours and 22 minutes. lol 

     

    Thanks. 

  • varjak paw Level 10 (169,822 points)

    Cloning your iMac's hard drive to the Thunderbolt drive would certainly be faster.

     

    Regards.

  • Smphoto74 Level 1 (5 points)

    Yeah, I've been running off of external SSD's(OS and apps) on my iMacs for a year now.  330mbps write and 490mbps read.  Can't complain about those speeds.  Just a shame it's not so plug and play with the new iMacs.  I used the Pegasus R4 for all my pics, videos so the SSD stays pretty free. 

  • babowa Level 7 (29,930 points)

    Just an additional note for future reference: in general, Macs have never been able to boot from a system older than what they came with with a few exceptions: machines that were made right around the time a new OS is released would mostly still be able to boot into the previous OS even though they may come loaded with the new version. In this particular case, you are also adding a different build = special OS build version, which complicates things further.

     

    Check for updates on this article - it doesn't even have the new iMacs yet:

     

    http://support.apple.com/kb/HT1633#

     

    Checking further, this article includes the new 21.5":

     

    http://support.apple.com/kb/HT1159