With the announcement of new iPads and iMacs and a refreshed Mac mini, Apple also released the final version of OSX 10.10 after multiple public betas. In case you are setting up multiple Macs or need an offline installer for older Macs that do not support “Internet Recovery” you can create an USB Installer. You will need the following:
- A Mac with OSX Mavericks/Yosemite installed
- 8GB or larger USB flash drive – preferably USB 3.0 if your Mac supports it
- OSX 10.10 Installer from the AppStore in the Appllications folder.
- Administative Access to your Mac (No restricted account)
Beware: All date on the USB key will be deleted (create a backup if necessary)
Using the Disk Utility format the Stick so it contains 1 HFS+ Partition and uses the GUID partitoning scheme (not the default MBR)
Leave the name “Untitled” as it is for now and format it using the Mac OSX Extended (Journaled) filesystem.
Open command line terminal and enter the following command
sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction
This command will erase the disk and copy over all necessary installation files. After a while the USB key will automatically be mounted and the volume will soon load the OSX installer. Additionally, a recovery partition has been created that may come in handy if the hard drive dives and not internet connection is available.