I guess it’s geeky to make a boot USB for Mavericks anyhow, but I thought I’d document this for my own sake and let the rest of you benefit.

This assumes you downloaded Mavericks and haven’t installed it yet but want to make a boot disk to be used to upgrade other Macs without downloading it over and over, or save yourself later on if your mac is unable to boot and you want to use this USB to fix it. I work in IT and need to upgrade a bunch of mac, here’s my instructions on how to prepare the USB drive with Mavericks.

This quick one liner also assumes that you downloaded and left it in /Applications and haven’t moved it or haven’t modified it’s filename (in orange below).

To create the USB boot drive you need the following:

  • An 8GB or larger USB flash drive
  • The OS X 10.9 Mavericks installer from the Mac App Store in your Applications folder. The installer will delete itself when you install the operating system, but it can be re-downloaded if necessary.
You'll want to go to Disk Utility and format it as a Mac OS X Extended (Journaled) formatted volume named "Untitled" (you can see the volume name below in green)

Then open a terminal window and run the following

sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia –volume /Volumes/Untitled –applicationpath /Applications/Install\ OS\ X\ Mavericks.app –nointeraction

The following will appear:

WARNING: Improper use of the sudo command could lead to data loss or the deletion of important system files. Please double-check your typing when using sudo. Type "man sudo" for more information. To proceed, enter your password, or type Ctrl-C to abort. Password: Erasing Disk: 0%... 10%... 20%... 30%...100%... Copying installer files to disk...

Once that is complete you should be able to boot from your new USB disk either by changing the default Startup Disk in System Preferences or by holding down the Option key at boot and selecting the drive. From there you can install Mavericks.