Yosemite Thumb Drive

A Mac Tech friend sent me a good article on how to make a USB Thumb Drive installer for OS X 10.10 Yosemite. Why would you want to do this? If you have to install Yosemite on several machines this is the only way to go. It is 5GB in size and takes forever to download.

You will need at least an 8GB Thumb Drive to do this. I had a 16 GB Thumb Drive so I partitioned it using the Disk Utility app like so:


I made the Yosemite partition 9GB to be safe. This needs to be a GUID partion. I will use the other 7GB to make an installer for Mavericks or some other OS. In the Mac Tech Support world it is good to have installers for several different Mac operating systems to install or re-install on older machines.

Starting with the Mavericks 10.9 OS Apple included a Unix app called createinstallmedia. That is what we are going to use to create the Yosemite installer. Keep in mind that createinstallmedia only works on machines running 10.7 Lion and above. This procedure presupposes that the Yosemite Installer downloaded from Apple is still in your Applications Folder. To make sure it is still there you need to QUIT the Yosemite install before it actually installs on your machine. That leaves the installer in your Applications Folder for this procedure. This process is looking for the Yosemite Installer in your Applications Folder and for your Thumb Drive to be named “Untitled”. Here are the steps by the numbers:

  1. Plug the Thumb Drive into your Mac. Make sure it is named “Untitled”.
  2. Open the Terminal Application in the Utilities Folder.
  3. Copy this text and paste it in the Terminal Application at the prompt and hit Return: sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia –volume /Volumes/Untitled –applicationpath /Applications/Install\ OS\ X\ Yosemite.app —nointeraction
  4. The procedure will show you it’s progress. It took about 20 minutes on my machine, YMMV. Here is what the process looks like:


This is taken from my Yosemite Thumb Drive creation. It gives you these percentages and tells you when it is done. This took me about 20 minutes on my iMac with an average speed thumb drive, YMMV. 

When this was completed I did a Tech Boot (hold down the Option Key ⌥ at the restart chime) and selected the Yosemite Thumb Drive and installed Yosemite on my iMac. Did the same procedure on our 2011 MacBook Air. No problems on either install. For info on the install process check my previous article.

This is a totally cool procedure. Downloading Yosemite for about 2 hours every time you need to install it is just a drag. This way you download it once, create the installer Thumb Drive and you can install it as many times as you wish thanks Apple making it FREE!

This is not a difficult procedure, give it a try if you have to install Yosemite on several machines.

Doug