I'd like to start from scratch with Yosemite. I have Mavericks running on my iMac now but I'd like to just wipe the system and start with a clean Yosemite install.

How do I do a clean install of Yosemite on my machine, not an upgrade install?

  • 2
    Stop flagging this. Yosemite is public now.
    – Ian C.
    Commented Oct 16, 2014 at 17:47

2 Answers 2


I downloaded the OS X Yosemite GM from the App Store. Quit the installer that pops up with out installing and made a bootable flash drive with it on it. Used the following command below just change the paths to fit your need.

sudo /Applications/Path to *Yosemite Installer*.app/Contents/Resources/createinstallmedia --volume /Volumes/*FlashDrive* --applicationpath /Applications/Path to *Yosemite Installer*.app --nointeraction

Then booted the computer to the usb flash drive and wiped the previous partitions using Disk Utility.app and installed a fresh copy.

  • 1
    This would be an even better answer if you mentioned how to get my data back on to it after doing the clean install.
    – Ian C.
    Commented Oct 16, 2014 at 18:03
  • Getting your user data back from Mavericks onto Yosemite after you do a clean wipe?
    – tron_jones
    Commented Oct 16, 2014 at 18:19
  • Yes. That's what I mean.
    – Ian C.
    Commented Oct 16, 2014 at 18:22
  • I would say copy what you want to an external drive or make a Time Machine Backup that you can dig through. I think doing a clean upgrade install is a tedious job if your looking to bring back certain pieces of an older OS IMHO.
    – tron_jones
    Commented Oct 16, 2014 at 19:50

I'd use a new HD, if you are ever thinking you may need to revert.
Yosemite appears to make your boot drive into a Core Storage Volume, making repartitioning difficult.

  • 1
    Not going to open up my iMac for this, but thanks.
    – Ian C.
    Commented Oct 16, 2014 at 17:56
  • 1
    ahh... iMac, fair enough. There's no way Yosemite is going onto my old boot drive in the foreseeable future. This may be the first time I've ever held off a new release - because even though I've 5 drives in here, only one is an SSD, my current boot drive, & I don't want to break anything before the initial flurry of 'oops & fixits' is over. Previously I've just cloned to a spare in case of unexpected 'oopses'
    – Tetsujin
    Commented Oct 16, 2014 at 18:07

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .