mattchu

Q: Yosemite won't boot seagate ext drive with snow leopard

I have a new 27" mac with yosemite and an ext seagate 3tb hard drive with snow leopard for those old apps I like to use. On previous mac I could boot into it and now I can't. I can see it and get to its contents but booting into it only gives a frozen grey screen with the apple logo. I hooked it up to a macbook running snow leopard and it booted into the drive just fine. Is it just Yosemite? If so, how do I fix it? Please help.

27" imac, Mac OS X (10.6.4)

Posted on Oct 3, 2015 11:44 PM

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Q: Yosemite won't boot seagate ext drive with snow leopard

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  • by joe_7399,

    joe_7399 joe_7399 Oct 4, 2015 9:19 AM in response to mattchu
    Community Specialists
    Oct 4, 2015 9:19 AM in response to mattchu

    Greetings mattchu,

     

    Thanks for being an Apple Support Communities member and for taking the time to ask this question! We’re glad you’re here and can’t wait to hear more from you! :) 

     

    It sounds like you are not able to boot from your external HDD, which has Mac OS X Snow Leopard on it, using your new Mac which is running Mac OS X 10.10 Yosemite. These type of issues can occur if your new Mac shipped from Apple running a later version of Mac OS X than 10.6 Snow Leopard.  

     

    The information in the following articles explains this information in more detail.

     

    Starting from an external USB storage device (Intel-based Macs) - Apple Support

     

    Intel-based Macs support starting from an external USB storage device's volume that:

    • Has been formatted with a GUID partition type
    • Contains an installation of Mac OS X 10.4.5 or later, or Mac OS X 10.5 or later, which is compatible with (or shipped with) the Mac that the USB device is connected to. NoteYou should not use a version of Mac OS X that is earlier ("older") than the version your Mac shipped with.

     

    Use the version of OS X that came with your Mac, or a compatible newer version - Apple Support

     

    We hope that these articles were helpful to you in explaining what may be causing this issue. We invite you to reply and let us know if this is the case or to provide any further information. We are here to help!

     

    All the best!

  • by Gary Scotland,

    Gary Scotland Gary Scotland Oct 4, 2015 10:08 AM in response to mattchu
    Level 6 (14,328 points)
    Desktops
    Oct 4, 2015 10:08 AM in response to mattchu

    The only way to run Snow Leopard on a newer Mac is explained here:    Snow Leopard Server in Parallels

    I have SL Server running in Parallels on a MacMini bought last year running Yosemite. It works fine but applications that use graphics acceleration do not run e.g. Keynote, Fotomagico