Complete Steps to Perform a Clean OS X Reinstall on Your MacBook Air

Discussion in 'MacBook Air' started by clayj, Feb 4, 2008.

  1. clayj macrumors 604


    Jan 14, 2005
    visiting from downstream
    NOTE: The most up-to-date steps are available in the following Guide entry: Please feel free to post your questions and comments in this thread.

    This guide is provided in order to make it easier for you to free up valuable hard drive/SSD space on your MacBook Air by reinstalling OS X with only the components that you really need. It is recommended that you perform these steps before you install a bunch of applications and data files, because these steps will reset your MBA's hard drive/SSD completely.


    • Insert your OS X DVD #1 into your SuperDrive (if you have one) or external, shared DVD drive (you must have set this up previously, following Apple's instructions and using the OS X DVD #1 in your remote machine to install Remote Disc).

    • Shut down your MacBook Air. Then, turn it back on and hold down either the C key (SuperDrive) or the Option key (Remote Disc) to boot from the OS X DVD. The Apple logo will come up and the "processing" whirly thing will go for a while (a few minutes, in my case).

    • The screen will eventually turn blue, and then you will see the nebula wallpaper and be prompted to select a language. Click "Use English for the main language", or select your appropriate language. Then, click the "-->" button. The Mac OS X Leopard Installer window will appear.

    • On the Utilities menu, click Disk Utility. The Installer window will disappear and the Disk Utility window will appear.

    • Once disk information has been gathered, select your hard drive. This will be the item ABOVE "Macintosh HD". In the case of a 64 GB SSD, the item should be called "55.9 GB MCCOE64GEMPP" or something similar.

    • Click Partition. Under Volume Scheme, select "1 Partition". In the Name box, type "Macintosh HD" or whatever you want your hard drive to be named. Then, click Apply. Click Partition to confirm repartitioning of the hard drive/SSD. It will take a few seconds for the drive to be partitioned. Once it's done, click Quit Disk Utility on the Disk Utility menu. The Disk Utility window will disappear and the Installer window will reappear.

      NOTE: If you fail to perform steps 4-6, you will not have a clean install, and it is possible that you will not be able to prevent applications from being installed.

    • In the Installer window, click Continue. Click Agree to agree to the software license agreement (you can read it first if you really, really want to).

    • In the "Select a Destination" window, select your hard drive ("Macintosh HD" or whatever you called it). Click Continue.

    • In the Install Summary window, click Customize (lower-left corner of the dialog box).

    • In the list of Package Names, you can turn OFF (uncheck) any or all of the following items, depending on whether you think you will ever need them:

      PRINTER DRIVERS (3.4 GB): You can opt to not install ANY printer drivers by clearing the Printer Drivers checkbox. You can also install just specific printer drivers by turning ON only the checkboxes for those printer drivers you think you might need (Hewlett-Packard, for example). In my test, I turned the Printer Drivers checkbox OFF and chose not to install ANY printer drivers; later on, I plan to manually install the printer drivers for my specific HP printer using the CD that came with the printer, and I don't need any other drivers.

      ADDITIONAL FONTS (141 MB): I don't ever need Chinese, Korean, Arabic, Hebrew, Thai, Cyrillic (Russian), Devanagari, Gujarati, Punjabi, Tibetan, Armenian, Cherokee, or Inuktitut font support for my own use, but I occasionally do hit web sites that use one or more of these languages, and it's only 141 MB... so I left this checkbox turned ON. If you want to save 141 MB because you're sure you won't need this, you can turn the Additional Fonts checkbox OFF.

      LANGUAGE TRANSLATIONS (1.8 GB): I definitely don't need any of these, so I turned OFF the Language Translations checkbox and chose not to install any of them. Individual languages may be installed by turning ON their checkboxes... each language is roughly 100 MB in size.

      X11 (117 MB): This option allows you to run Linux and UNIX apps in OS X. I don't think I'll ever do this, but I left the option checked since it's only 117 MB. (EDIT: Thanks to mzd for explaining what this option does.)

      BUNDLED APPLICATIONS (3 GB): This contains many separate items which you may or may not want to install:

      • CPU HELP FILES (262 MB): This is the user's manual for the MBA and for Leopard, so this is probably a good thing to install.
      • IWEB (290 MB): I don't use iWeb for web design. Ergo, I cleared the checkbox for iWeb and chose not to install it.
      • GARAGEBAND (1 GB): I don't really use GarageBand except to make ringtones for my iPhone... and I'll be doing that on my Mac Pro. So, I cleared the checkbox for GarageBand. Note that the "GarageBand Additional Instruments and Loops" option (1.3 GB) is turned OFF by default.
      • IDVD (559 MB): No built-in optical drive = no making DVDs on my MacBook Air, so I cleared the checkbox for iDVD. As with GarageBand, the "iDVD Extra Content" option (342 MB) is turned OFF by default.
      • IPHOTO (553 MB): This was a tough one for me. I don't plan on managing my photos on my MacBook Air, but I can see where I might want to at some point. So I left this checkbox turned ON.
      • IMOVIE (136 MB): As with iDVD, I can't see using iMovie on a machine with no optical drive built-in (although I suppose you could just author movies and then burn them when you get home). At any rate, I don't ever use iMovie, so I cleared its checkbox.

      By my reckoning, turning OFF the items listed in blue above should have saved me 7200 MB or so (7 GB?) in disk space (actual numbers below).

    • Once you've made the changes you want, click Done. Then, click Install. Click Continue Installation once you verify you have both OS X DVDs.

      You can click Skip if you want to skip the DVD consistency check. This will save you a lot of time in the installation process. I clicked Skip and was told that installation would take roughly 40 minutes to 1 hour.

    • When the Installer is done with OS X DVD #1, the MacBook Air will automatically restart and eject OS X DVD #1. When this occurs, go ahead and insert OS X DVD #2; YOU MAY NOT BE EXPLICITLY TOLD TO INSERT THE DVD. Insert the DVD and installation will continue automatically for about 10 to 20 more minutes. When installation is complete, you will be prompted to click Continue.
    OS X DVD #2 will be ejected and your MacBook Air will automatically reboot and you will go through the normal first-time experience (selecting language, entering Apple ID, creating user account, etc.).

    Following these steps, I went from:

    Used = 18,563,555,328 bytes
    Free = 38.29 GB


    Used = 10,813,370,368 bytes
    Free = 45.51 GB

    for a total savings of 7.22 GB! That's almost a 19% increase in free disk space, and it only took about an hour and a half to do. Turning off other options which I chose to install might have saved me about 1 GB more.

    Note that once you have installed the above, you will still need to install OS updates (OS X 10.5.2, etc.) and application updates using Software Update.

    Hope these steps help... please post your comments here and I will update these steps as necessary.

    Deleting the Alex voice (thanks to actuality for that tip) would free up almost another 700 MB, but this can be done at any later time. And using the steps that Salty Pirate documented below would free up another 2 GB, but I don't want my system crashing if I let the battery completely drain, so I am passing on that for now.

    If later on you want to install something you chose not to install using the above steps, you can insert the OS X DVD #1 into your DVD drive (SuperDrive or shared Remote Disc) and then double-click Optional Installs > Install Bundled Software Only > Continue > Continue > Customize. This will let you (re)install the CPU Help Files, iWeb, GarageBand, iDVD, iPhoto, and iMovie.

    Click here for some handy information about how to store your files on a different machine and still be able to access them from your MBA.
  2. treacle macrumors newbie

    Jul 19, 2002
    metro New York area
    It's worth doing this now when the MBA is new. Those few extra GB will mean alot more later and you will be glad you did this.
  3. noservice2001 macrumors regular

    May 7, 2006
    808 State
    wow... this should be a sticky, and made into a printable version... nice
  4. ubercool macrumors 6502a


    Jan 31, 2008
    Las Vegas
    Is it my imagination or is this the sloooooooooooowest process in the world? :(
  5. MazingerZ macrumors 6502


    Aug 22, 2007
    Huh? These are the steps to reinstall the OS. Nothing surprising on how long it takes.
  6. matthewHUB macrumors 6502

    Nov 29, 2005
    Wirelessly posted (iPhone: Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420.1 (KHTML, like Gecko) Version/3.0 Mobile/4A93 Safari/419.3)

    anyone got any info on whether it's safe to delete the things the OP was unsure of? Like those help files? Etc?
  7. Eric Lewis macrumors 68020

    Eric Lewis

    Feb 4, 2007
    CANADA? eh?
    yes stickie...people will ask this 100x times
  8. maroulis macrumors member

    Sep 27, 2006
    i'm about to scream.. migration assistant took forever over 802.11N and I decided to stop... Now doesn't boot up, I get a blue screen w/nothing on.. Trying to install remotely from my Macbook using the Macbook Air install CD 1 and running "Remote Install OS X", I select the CD it boots and then again the frickin blue screen w/nothing else !!!!

    Any suggestions?

    PS my apple store didn't have USB Drive
  9. steve31 macrumors 6502a


    Jul 20, 2007
    Edmonton Canada
    HEY a BIG thanxs to you "clayj" :D:D:DI have not got my 1.8 ssd yet but I will be using this as a guide when I get it. You saved me a lot of guess work.;)
  10. Photography macrumors 65816


    Apr 10, 2007
    Used this guide on my Air and it worked perfectly. :) Thanks clayj! This should be stickied, I agree.
  11. aiongiant macrumors 6502a

    Aug 8, 2006
    wow awesome! i will def use this when i get my air hehe

  12. happyslayer macrumors 6502a


    Feb 3, 2008
    Glendale, AZ
    Wow... sweet post. I just ordered my new MBA 1.8/SSD tonight (about an hour ago!) and will be using this guide within minutes of opening the box!

    I am a PC/Windows guy most of the time and reinstalling OS X for tightness is not my forte' so thank you so much!
  13. loghyr macrumors member

    Feb 1, 2008

    Okay, it restarted and I didn't let it eject the first DVD. I went ahead and ejected it myself (too used to other OSes).

    It went straight to the Welcome menu.

    Do I have a failed install?
  14. loghyr macrumors member

    Feb 1, 2008
    BTW I did not have it install iPhoto, but otherwise made the same selections.

    I've got 9.2G used, which seems off.

    You had 10.8 - .6 (for iPhoto) = 10.2G

    I seem to be missing a G of stuff.

    You don't need an Apple USB drive, I used a Sony 810U external drive. (Note that while it is nowhere near as portable as what Apple probably offers, the price was right - already paid for a couple of years ago. :cool:)

    It did freeze the first time through saying to clean the media.
  15. maroulis macrumors member

    Sep 27, 2006
    this is insane... I still can't get it to work I must have tried over 30 times now from my macbook (latest revision) sharing the install DVD starting up holding down option key, selecting WLAN, etc then the disk which it can see...

    only ONCE did it actually go through the proper set-up and then hang again..Am I the only one?
  16. Salty Pirate macrumors 6502

    Salty Pirate

    Oct 5, 2005
    kansas city
    Here is another space saving tip....about 2GB.

    The Macbook's come from the factory in hibernate mode 3. It writes the contents to the disk. That facilitates battery removal and replacement on MBP machines. Well we are never going to swap batteries, so hibernate mode 0, write to memory, makes more sense. You can also rm the disk space taken up by the hibernate image.

    Follow these simple commands:

    This command will tell you what mode you are in:

    pmset -g | grep hibernatemode

    Then change to mode 0. A 3 will take you back to where you were.

    sudo pmset -a hibernatemode 0

    This command removes the sleep image and reclaims very valuable SSD space.

    sudo rm /var/vm/sleepimage

    reboot and you are done.
  17. kkat69 macrumors 68020


    Aug 30, 2007
    Atlanta, Ga

    • With the exception of a few peculiars regarding the hardware specific drives (mainly the bold part in step 1 which didn't get into much detail), etc. Isn't this just a "clean install" of Leopard process? Something a lot of us have already done or should at least know how to install OSX. For that matter it's not even THAT Leopard specific.

      Good job writing the stuff down though. Pretty much just the same way you would do a fresh install almost any OSX on any Mac.

      If anything this should be (unless it already has something similar) stickied in just a Mac software location. It's not really MBA specific.
  18. kyleen66 macrumors regular

    Jan 29, 2008
    I'm sure this takes awhile.

    How long is expected? I plan on doing this, but with my insane schedule, I need to plan the time.

    Excellent info though! I appreciate it!
  19. MRU Suspended


    Aug 23, 2005
    Cheer's for posting that Clayj... There will I imagine be a lot of posters requesting that info in the forthcoming days / weeks.

    (I always do a fresh install on any mac hardware I get - execpt my macpro as I really didn't worry about 6-7gb on a main 500gb HDD ;) - but for laptops it's a must do for me.)
  20. clayj thread starter macrumors 604


    Jan 14, 2005
    visiting from downstream
    Salty, good stuff. Can you also post the "reverse" steps for if someone wants to go from mode 0 back to mode 3? If you can, I will try both sets of steps and see about adding them to the master steps above as an option.

    One question: If you switch to mode 0 and your battery totally dies, am I correct in assuming your computer will not hibernate, but simply crap out as if you had yanked the battery out while it was still running? If so, is that a big problem as far as the operating system or file integrity are concerned?

  21. Salty Pirate macrumors 6502

    Salty Pirate

    Oct 5, 2005
    kansas city
    Executing this command will take you back to mode 3 and disk write sleep image:

    sudo pmset -a hibernatemode 3

    Yes, the one downside, if your battery completely dies, it would be like a system crash. Perhaps battery conditioning should be done before this change is made.

    Just remember, in mode 3, your sleepimage on the disk will be close to the size of system RAM, in our case 2 GB.
  22. noservice2001 macrumors regular

    May 7, 2006
    808 State
    am i a n00b? is this english? i'm lost

    can you explain how to get to this menu? er. how to get to "command"?

    and why won't the mods want to make this a sticky? this is top notch info... its even grammar fixed and everything
  23. MRU Suspended


    Aug 23, 2005
    Use Terminal in the Utilities folder in Applications.
  24. noservice2001 macrumors regular

    May 7, 2006
    808 State
    oh, its like dos... coolness!
  25. kming05 macrumors member

    Jan 27, 2008
    hey everyone. sorry i'm a mac newbie, but i'm wondering if there is another way to just delete some of the bundled applciations without doing a fresh reinstall?

Share This Page