How do I do a clean install of Yosemite?

Discussion in 'OS X Yosemite (10.10)' started by Mr. RPG, Jul 24, 2014.

  1. Mr. RPG macrumors 6502a

    Joined:
    Sep 21, 2012
    #1
    I just downloaded the Public Beta but how do I do a clean install of the OS? i've never had to reinstall OS X or anything before.
     
  2. tywebb13 macrumors 68020

    Joined:
    Apr 21, 2012
    #2
    Do a time machine backup first. Then make a bootable usb installer using instructions in this thread: http://forums.macrumors.com/showthread.php?t=1757723

    Start up your computer with holding down the option key and boot up from the installer.

    Then use the disk utility in the usb installer to erase the drive and then install Yosemite from the usb onto the newly erased drive.

    Alternatively, you could make a separate partition and install to that instead.
     
  3. Mr. RPG thread starter macrumors 6502a

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    Sep 21, 2012
    #3
    I don't have a USB with enough storage I'm afraid..

    Is there no way to simply re-install from the Public Beta without using a USB boot?
     
  4. BasicGreatGuy Contributor

    BasicGreatGuy

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    In the middle of several books.
    #4
    I would definitely install it on a separate partition.
     
  5. SanFran95 macrumors member

    SanFran95

    Joined:
    Jul 18, 2014
    #5
    Don't know if this also works with OS X Yosemite, but maybe: http://support.apple.com/kb/HT5943
    - But wouldn't make a clean install with a Beta unless I had a good backup - it'll be more stable/'safe' to do it when the final version is released ;)
     
  6. thisoldnerd macrumors newbie

    Joined:
    Jul 24, 2014
    #6
    I get this error about a second after entering my password. I have used a lacie (8GB) and sandisk (32GB) thumbdrive formated, MACosEJ

    open terminal and copy and pasted the string and then nothing.

    Password:
    Erasing Disk: 0%... 10%...
    Error erasing disk error number (-69888, 0)
    A error occurred erasing the disk.
    iMac:~ user$



    can someone please advise?
     
  7. vitaligent macrumors newbie

    Joined:
    Dec 25, 2013
    #7
    I had this exact error. For me, it was because I had specified the wrong partition name in the command line:

    "createinstallmedia --volume /Volumes/Untitled"

    You need to check in your /Volumes folder to make sure you're providing a valid path to your blank USB drive.

    Hope that helps.
     
  8. Mr. RPG thread starter macrumors 6502a

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    Sep 21, 2012
    #8
    Does anyone know if you can do this with the Yosemite Public Beta?
     
  9. VirtualRain macrumors 603

    VirtualRain

    Joined:
    Aug 1, 2008
    Location:
    Vancouver, BC
    #9
    I used this to create a bootable Yosemite USB stick installer which I've used to do clean installs on two Macs now. Backed up both systems with CCC before of course.

    http://liondiskmaker.com
     
  10. merlino165 macrumors newbie

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    Jun 14, 2014
    Location:
    Trieste - Italy
    #10

    of course no ! mentioned procedure only reinstall existing Operative System

    if Recovery Partition owns to Mavericks, it will download and reinstall Mavericks

    for a clean install you have to use any USB drive !
     
  11. smokesletsgo macrumors regular

    Joined:
    Oct 23, 2013
    #11
    You don't need no USB installers. CMD + R, format the drive and install/download Yosemite from there. Installs perfectly just like any other OS X, tried it.
     
  12. merlino165 macrumors newbie

    Joined:
    Jun 14, 2014
    Location:
    Trieste - Italy
    #12
    only if you have already installed Yosemite before and Recovery Partition owns to it
    if he needs to perform a clean install from Mavericks has to use a USB installs
     
  13. Mr. RPG thread starter macrumors 6502a

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    Sep 21, 2012
    #13
    Agh, which one of you is correct?
     
  14. merlino165 macrumors newbie

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    Jun 14, 2014
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    Trieste - Italy
    #14

    if you have already installed Yosemite, and need to perform a clean reinstall, the suggested procedure is correct

    if it's the first Yosemite install, there is no way to use a Recovery Partition related to a previous System, to download a new one

    You need a USB drive, to prepare a bootable Installer !
     
  15. DeltaMac macrumors 604

    DeltaMac

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    Jul 30, 2003
    Location:
    Delaware
    #15
    Both are correct - which method to use, is your choice.

    You can erase the hard drive OS X partition while booted to the Recovery partition, which you already have. (That's restarting with Command+R)

    Or, you can boot to an installer, on a USB device, for example, and erase/install from that installer. That will require a little preparation, as you need to have the installer downloaded, then create the installer on a USB flash drive, or some other drive that you might already have. It might even be a good excuse to spend less than $10, and get an 8GB USB flash drive, that you can dedicate to this purpose…
    Erase & Install from your created USB partition/drive will be quicker, as you don't have to wait for the system files to download through your internet connection, so I prefer the bootable installer, too...
     
  16. Mr. RPG thread starter macrumors 6502a

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    Sep 21, 2012
    #16
    I haven't installed Yosemite before though, so is method 1 still usable? I've only downloaded it.
     
  17. DeltaMac macrumors 604

    DeltaMac

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    Location:
    Delaware
    #17
    If you already have the installer - that will work, just launch it.
    Your downloaded installer WILL delete itself when it is finished.
    If you REALLY want to do a fresh install (that's erase the drive, then reinstall, so nothing from your present drive still is present), then best to make a USB flash drive as a bootable installer.
    Again, less than $10 for an 8GB USB flash drive is all you need.
    Download the DiskmakerX, which will make the process simple.
    http://liondiskmaker.com
    You'll notice that DiskmakerX for Yosemite comes in two different versions. One for the Beta, and one for the Developer Preview. Make sure you get the app that matches up with what you downloaded for Yosemite.

    Remember that a "Clean Install" means that your present files/pictures/music will all disappear -
    After booting to the installer, erase the hard drive using Disk Utility from the installer window. Quit Disk Utility after erasing the hard drive, then continue with the OS X install.
    And, there's your fresh install of OS X 10.10...
     
  18. Weaselboy Moderator

    Weaselboy

    Staff Member

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    Jan 23, 2005
    Location:
    California
    #18
    If you have never installed Yosemite then you do not have a Yosemite recovery partition, so a command-r boot to recovery is not going to get you Yosemite. You will need to make the USB installer and boot from it then erase the disk and install to get your clean install of Yosemite.
     
  19. Mr. RPG thread starter macrumors 6502a

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    Sep 21, 2012
    #19
    I'd really prefer not to do a USB installer though.

    Could I just install Yosemite, erase the hard drive, then use recovery to re-install Yosemite?

    or any other way that doesn't require a USB?
     
  20. Weaselboy Moderator

    Weaselboy

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    #20
    Sure that will work. Just a double download of the data as long as that does not bother you.
     
  21. Mr. RPG thread starter macrumors 6502a

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    #21
    Why would I need to download anything..?
     
  22. Weaselboy Moderator

    Weaselboy

    Staff Member

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    Jan 23, 2005
    Location:
    California
    #22
    Well you already downloaded the installer, so you can just run that now and install over top of Mavericks and that will create a Yosemite recovery partition that can be used to install Yosemite.

    So then you will command-r boot to recovery and you will then be running from the Yosemite version of the recovery partition. Then you erase Macintosh HD and click reinstall OS. When you do that it will redownload Yosemite and install it. It is this second DL of the OS I was referring to.

    When you boot to recovery to reinstall there is no way to reuse the installer you already downloaded, you will need to let the recovery system download another opt to be installed.

    Disclaimer: This is how it works in recovery on prior OS versions, and from what I have read here Yosemite works the same way, but I have not tested this myself with Yosemite.
     
  23. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #23
    The installer files are not kept on your computer, except for the initial installer app.
    If you install Yosemite, just to erase, then reinstall yosemite - your initial installer app is gone (deletes itself after the install), and all the system files get downloaded again.
    You can copy your downloaded Yosemite installer app to another drive, so you'll still have that copy (meaning you'll need some kind of external storage anyway :D )
    Try to rethink about the USB installer. The process will keep the installer local, so you can reinstall, even without an internet connection. The DiskmakerX app is very simple to use, and then you have your installer whenever you might need to use it (along with an independent location for a few simple utilities that you might like to have, particularly if your hard drive has to be replaced.
    And, an 8GB thumb drive is less than $10. I must have 20 of those (good bargain a few months ago :D ($4 each, got 5 then)
     
  24. Mr. RPG thread starter macrumors 6502a

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    Sep 21, 2012
    #24
    Alright guys I'll just do the bootable USB installer. Thanks for the information!
     
  25. 537635 macrumors 6502

    Joined:
    Mar 7, 2009
    #25
    I read in another topic, that beta version of Yosemite does not upgrade the recovery partition.

    Can somebody please confirm whether it does or doesn't? I would rather just upgrade and then do the fresh install via cmd+r.
     

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