HELP! How would you clean install Lion if you are upgrading from Snow Leopard?

Discussion in 'Mac OS X Lion (10.7)' started by ProPedderKustom, Jul 26, 2011.

  1. ProPedderKustom macrumors regular

    Jan 11, 2008
    I want to upgrade my Mac mini from SL to Lion. I know I can just download it from the App Store to do this. But what happens if I have Lion, and then want to wipe my HD and do a fresh install of Lion? How would this be accomplished?

    This closest thing I can find is using Lion's recovery partition to do an internet install. But is this recovery partition hidden enough from Disk Utility so that I don't accidentally wipe it with everything else?

    I want to upgrade but I need to know how this would work in a world without disks or USB drives.
  2. angelwatt Moderator emeritus


    Aug 16, 2005
    A true clean requires the internet to connect to Apple to download additional files. If you want to ensure the recovery partition is gone, you can use a Snow Leopard install disk or a Linux live CD to boot off of.
  3. dfine1966 macrumors 6502

    Apr 9, 2011
    You do know you can download Lion from the App Store in SL, create a DVD or Bootable USB drives with the download.

    Here is a link of directions on how to do it. It is very easy to do a clean intall. These direction are for DVD boot disc, but you can do the same for USB drive.
  4. HiRez macrumors 603


    Jan 6, 2004
    Western US
    It does seem odd that they made Safari available on the recovery partition (a good thing), but didn't do the same for App Store (I don't think App Store is in there, is it?)
  5. angelwatt Moderator emeritus


    Aug 16, 2005
    Not that I saw. I rummaged around quite a bit when I had issues doing the clean install. I was surprised to see Safari though, but I guess it's making use of it's pieces to make the Apple Store call behind the scenes.
  6. shinji macrumors 65816


    Mar 18, 2007
    I bought Lion and copied the installer app to another drive. Then I reformatted, installed Snow Leopard from DVD, upgraded to 10.6.8, and then copied the installer to /Applications/, and then upgraded.

    I made the bootable flash drive before reformatting, but ended up not using it because I read somewhere that doing this doesn't create a recovery partition that you would get it if you do it the normal way.
  7. mr666 macrumors regular

    Sep 14, 2009
    Term is "Erase and Install". Look in the Options screen of any OS 10.5.8 or earlier installer. A "Clean Install" is a new OS 9 System Folder. It is the install that is clean, not the HDD file system.

    The equivalent term in OS X is "Archive and Install" (no longer mentioned in words in the OS 10.6 or later installer, but it still happens).

    ProPedderKustom: You get the full benefit of all new system from archiving everything (hiding all old directories in a new directory) rather than erasing. Then your old user documents are kept. You only need to erase a HDD when it has file system issues that Disk Utility cannot fix, or if you don't have enough available space for an archive and you want to act quickly to create space.

    As to how you can archive or erase, boot to the full-install DVD (OS 10.6). Apple is trying like heck to present Lion as both a new reference release and as requiring OS 10.6.6 or later to be already installed. If we were to believe Apple, we would boot to the full-install DVD to erase or archive (called "install" in the OS 10.6 DVD installer). When that is done, install the 10.7 "paid updater".

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