A True Clean Install

Discussion in 'OS X Yosemite (10.10)' started by dsemf, Nov 1, 2014.

  1. dsemf macrumors 6502

    Jul 26, 2014
    There have been recommendations in a lot of threads to do a clean install. Most of the them the talk about restoring from TM or using Migration Assistant.

    That is not my definition of clean install.

    After installing OS X using a USB drive with a disk format, these are the steps I use.

    Note: I don't use the admin account for any day to day activity.

    • Install third party apps from the Mac App Store or OFFICIAL third party sites. This does mean that licenses and keys will need to be applied. YOU DID keep them, didn't you?
    • Copy the user data from the backup media to /Users/<username>. DO NOT copy ~/Library.
    • Create each user referencing /Users/<username> as the home directory location. Try to create the users in the same sequence as before so that the UNIX UID numbers are consistent. I have not tested whether creating users against an existing home directory structure changes the file ownership.
    As each user logon occurs, the ~/Library will be created with a clean set of defaults. This does mean that each user will have to go through all of the System Preferences and set them as desired. This will also apply to all of the applications.

    The one exception that I have found to excluding ~/Library is iBooks. These are stored at ~/Library/Containers/com.apple.BKAgentService. With the move to more things being stored in Containers, this is getting more complicated. This also means that excluding ~/Library will become less possible. Containers currently has 49 entries on my system.

    This process worked very nicely for me, but it takes a lot more effort. I also have a fairly simple setup since email, calendar and contacts are all web based with syncing to the Mac setup after the fact. Safari bookmarks are synced with my iPhone using iCloud so that updates the new Mac install automatically.

  2. dsemf thread starter macrumors 6502

    Jul 26, 2014
    One thing I forgot to mention.

    If you are doing a clean install to address a particular problem, such as slow/dropping wifi, multi-display issues, serious lagging, etc., test those out before doing anything else. This will help identify whether the problem is truly the OS and/or hardware or the resulting environment when everything else is in place.

  3. ABC5S Suspended


    Sep 10, 2013
    Effort yes, but this method you posted is exactly what I do and I personnaly have had no issues like so many others. But, many will not take the time upon a first OS X release to do it right.

    Thank you OP for this. Too bad most will not see or read it. Others will disagree with it as well.
  4. meh... macrumors newbie

    Jul 6, 2014
    I do the same each time OS X has a major upgrade 10.6 - 10.7 - 10.8 - 10.9 - 10.10 & have never had the problems I read on the forums. Every time I offered that advice I get jumped on saying how un-necessary it is!

    I continue to do this as I enjoy the clean up of my systems every so often, I administer 4 Macs at home so it definitely is a task but worth the initial investment in my opinion. This gets rid of all the fluff I accumulate & never use... keeps my Macs lean & mean!
  5. leman macrumors G3

    Oct 14, 2008
    The only reason to go through all that hassle is if s normal upgrade does not work for you for some reason. We have upgraded over a dozen Macs to Yosemite in the office without any issues at all. The installer does a pretty good job.
  6. b0fh666 macrumors 6502a


    Oct 12, 2012
    well i just upgrade from the working osx and never had any probs... lion onwards.
  7. dsemf thread starter macrumors 6502

    Jul 26, 2014
    Just to be clear: There is nothing wrong with deciding to do a standard upgrade. That is what I usually do. If, however, you want to start fresh, make sure that you don't subvert your intentions.

    This time I knew there was a lot of old stuff (applications, etc.) I wanted to get rid of and I decided the best method was a clean install so that there would not be any residual stuff left behind. I also knew that a number of applications where going to need upgrading.

    I actually did a hybrid clean install. The admin and main user accounts were clean installs, but another account that is only used for a single specific function, was not.

  8. grahamperrin macrumors 601


    Jun 8, 2007
    Definitions of clean

    If the installation is not performed with the installer provided by Apple – in its entirety – I might not treat the installation as clean.

    The first or the second would make the installation not clean.

    With a clean installation of the operating system, the first user will be be created as part of the Setup Assistant routine.


    In rare situations, a clean installation may be required for troubleshooting purposes. It's rarely requested, but in such situations it's important to realise the things that may make the test/troubleshooting environment less than clean.
  9. dsemf thread starter macrumors 6502

    Jul 26, 2014
    Good points. Thanks.

    I needed to be clearer in my descriptions.

    The USB Disk is created using the Apple supplied bootable install method: createinstallmedia

    The first user created is the admin user. This user has NO data restored. The daily non-admin user has all of their data, except for ~/Library, restored. If necessary, some parts of ~/Library may need to be restored for those apps which store their data in ~/Library, such as iBooks.

    The third party software installs need to occur later in the process, especially if trying to diagnose issues that could be affected by third party software. I forgot about the fact that some installs add things such as kexts, LaunchAgents and LaunchDaemons.

  10. bk01eeh macrumors newbie

    Oct 24, 2014
    Where did the disk format occur and how did you do it? EH
  11. dsemf thread starter macrumors 6502

    Jul 26, 2014
    After you boot from the install USB drive and the "To set up the installation of OS X" screen is displayed, select "Utilities > Disk Utility" from the menu bar.

  12. bk01eeh macrumors newbie

    Oct 24, 2014

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