Multiple OSs on a single USB Drive

Discussion in 'OS X Mountain Lion (10.8)' started by Achiever, Aug 1, 2012.

  1. Achiever macrumors 6502

    Achiever

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    #1
    I want to put both 10.7 and 10.8 Installers onto a single USB drive. So long as I create multiple partitions on the drive before I start moving each OS into a respective partition, is there any reason this wouldn't work?
     
  2. Achiever thread starter macrumors 6502

    Achiever

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  3. heisenberg123 macrumors 603

    heisenberg123

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    #3
    It would take less time to try than to bump if it doesn't work you will still have the 2 install DMG files
     
  4. Weaselboy Moderator

    Weaselboy

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    #4
    It will work. Just create two 8GB partitions and install each to its own partition.
     
  5. deeddawg macrumors 604

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    #5
    It's possible the OP doesn't have a big enough flash drive on hand to try it and is curious to know if it'll work before going out to buy one.
     
  6. Achiever thread starter macrumors 6502

    Achiever

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    #6
    Thank you. Does each have to be 8 gb? Can't a 16 gb be partioned into a three 5 gbs partitions to make room for the future 10.9 installer?
     
  7. Weaselboy Moderator

    Weaselboy

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    #7
    Yes, each OS installer requires an 8GB partition. This free app makes it real easy to make the USB installer key.
     
  8. VTECaddict macrumors 6502

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    #8
    It should work as long as the contents of the InstallESD.dmg fits. No need for each partition to be 8gb.
     
  9. Mal macrumors 603

    Mal

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    #9
    The partitions do not need to be 8GB each. I have installers for 10.7 and 10.8 plus DiskWarrior on a single 16GB flash drive. 10.7 is a 4.7GB partition, 10.8 is an 8.5GB partition with 3.5GB free (I was reusing another partition, so I could shrink it if needed). Snow Leopard did take an 8.5GB partition, because it was on a dual-layer DVD before. Lion shrunk the installer size, fortunately, and Mountain Lion raised it back up only a little (4.5GB to 5GB).

    jW
     
  10. Weaselboy Moderator

    Weaselboy

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    #10
    That makes sense, I was locked into thinking in terms of USB sizes, and knew a 4GB would not work. Hypothetically, if someone sold a 5GB USB key that would work for Lion I suppose, so the partitions are logical.
     
  11. Tinmania macrumors 68040

    Tinmania

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    #11
    It does not require 8GB partitions. I have ML on a 5.5GB partition with a gig left over and Lion on a 4.5GB partition.

    Why would it require 8 gigabytes?



    Michael
     
  12. heisenberg123 macrumors 603

    heisenberg123

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    #12
    correct I think most people just say it needs 8GB because 4GB is not enough and its easier to find 8GB USB drives than 6GB but your correct when talking partition size on a larger storage 8GB is more than you need
     
  13. Weaselboy Moderator

    Weaselboy

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    #13
    Did you read what I posted. I already explained my wrongheaded thought process.
     

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