Clean SL install on Lion machine without losing data ?

Discussion in 'macOS' started by Bloodyrockgod, Jan 2, 2013.

  1. Bloodyrockgod macrumors newbie

    Jan 2, 2013
    Is it possible to do a clean install of SL on a Lion machine without losing data.
  2. maflynn Moderator


    Staff Member

    May 3, 2009
    Yes, by backing up your data. BY definition a clean install means reformatting the drive and installing the OS on a blank drive
  3. justperry macrumors G3


    Aug 10, 2007
    In the core of a black hole.
    Isn't there an option anymore to install in place, or archive and install?


    Another way to get around having a backup is to resize the boot Volume, then create a new partition on the HD, Install SL on the new empty Volume, import all your Data to it, delete the original partition and resize the new Volume to the full space, this is a long process and an easier option is to backup to an external then wipe.
  4. maflynn Moderator


    Staff Member

    May 3, 2009
    I'm not sure to be hones, but archive and install is not a clean install, that is your home folder and network settings are retained. Its close to a clean install but its not exactly a complete clean install. Cruft from before still resides on the system to give the users headaches.
  5. benwiggy macrumors 68020

    Jun 15, 2012
    "Clean install" and "without losing your data" are two mutually exclusive things.

    A clean install means erasing everything and installing a brand new OS, with no user data, settings, third-party software, etc.
    "Not losing your data" means keeping everything (except the new OS) as it was.

    Since Snow Leopard, the OS installs "in place" -- what used to be the option of "Archive & Install" -- by default. In other words, it just updates the OS and keeps all your files, settings and software intact.

    But of course you will have a backup anyway, in case something goes wrong. Won't you?

    However, you can't do a normal install to DOWNGRADE the OS. First of all, you need to check that your machine can run Snow Leopard. If it is too new, then SL won't have the necessary drivers inside it.

    If you are downgrading, then you would be better off doing a clean install and then migrating your user data from your backup.
  6. blatopilot macrumors regular

    Sep 24, 2011
    If your machine came with Lion it is trickier than just inserting the disc.

    If your machine is from 2011 it likely can be done. I did it with mine.

    You need a machine running Snow Leopard (10.6.7 or higher I think), external hard drives, and carbon copy cloner or some other cloning software.

    You would need to make at least one clone of current your Lion machine on an external drive, confirm it works, and put it aside. By cloning I mean copy all files and delete anything that isn't on the source. One the Snow Leopard machine make sure you have an account or create one temporarily. Clone that to a fully separate external drive (not a partition on the Lion one). Once you do that plug it in to your Lion machine with Firewire and restart holding the Option key and select the external drive to boot up.

    If your Lion machine boots into snow leopard you know its good. Then you need to fully delete the Lion machine, including any hidden partitions and clone the snow leopard machine to the now former Lion machine.

    It's harder than it seems and you can't be sloppy, but I'm so glad I did it.

    *Disclaimer, I know this works on a early 2011 Macbook pro. Be very careful and research for a while before you jump the gun. There is more than one way to do this but they all involve time and diligence.... And have backups everywhere just in case!

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