OS X 10.9 "Mavericks" Installation Media Creation

This process is identical for Mac OS 10.10 Yosemite (replacing all instances of "Mavericks" with "Yosemite")

OS X 10.9 "Mavericks" is only available from Apple's App Store and at no cost.

Described below are procedures to produce installation media for OS X 10.9 "Mavericks" from the "Install OS X Mavericks.app" downloaded from the App Store. Unlike Mac OS 10.7, you can not simply restore the InstallESD.dmg image to a flash drive, you must use the createinstallmedia application.

1. Download "Install OS X Mavericks.app" from the App Store.
2. Mount your installation volume (usually a flash drive)
3. Open Terminal
4. Run createinstallmedia

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

   • Typically, Install OS X Mavericks.app is stored in /Applications but can be stored elsewhere, --volume needs to be pointed towards your installation volume (in this case a flash drive called "Untitled")
5. Confirm when asked to wipe the installation media and wait for the process to complete

"Corrupt Installation" Error Message

Occasionally, the booted installer will complain about being corrupt and will refuse to install. If this occurs, check your system time. If the time is not correct (can be caused by a dead clock battery) then the certificates will not match up.

Unfortunately, the Mac OS X installer (or recovery partition) does not include System Preferences making it slightly more difficult to fix the time. We can fix the time by using Terminal.

1. Open Terminal (this should automatically set you as root)
2. Run the date command to see the current date
3. Run the date command with the correct date as an argument
   • The date command runs in the format

     date {month}{day}{hour}{minute}{year}

     so December 5, 2014 at 7:30 AM would be 1205073014
4. Re-run the Mac OS X installer