Since the Mac app store was introduced, all the OS releases and updates have been directed through it. This is why, unlike Windows, you don’t get a permanent physical copy of the OS release. However, you can create a bootable installation of Yosemite or any other OS X release on a USB drive.
This method of creating the bootable Yosemite installation comes in very handy in crisis or when you are trying to install the OS on a different Mac without downloading the huge 5GB package again. It is always good to have a bootable backup handy!
You need a USB flash drive (a pen drive) with 8GB minimum storage. Download OS X Yosemite from the Mac App store. Make sure that you complete this process before proceeding with the installation as the system deletes the downloaded installation files after you’ve installed the new update.
Okay. So now you need to format the USB drive with ‘Mac OS Extended (Journaled)’ file system and name it ‘Untitled’. Open the terminal and type the following:
sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia –volume /Volumes/Untitled — applicationpath /Applications/Install\ OS\X\ Yosemite.app –nointeraction
Then press [Return]. The process will continue after you type in the administrator password. It will take around 20-30 minutes for completion.
Pretty simple, isn’t it? Try it out and let me know if you have any questions in the comment section below.