Create an installation USB for OS X 10.9 (Mavericks)

October 2016

The official support page for MacOSX Mavericks

Support page of Apple's Mavericks:


Compatible Macs:
  • iMac (as from mid 2007 or newer models)
  • MacBook (Late 2008, early 2009 or newer models)
  • MacBook Pro (Mid/late 2007 or newer models)
  • MacBook Air (Late 2008 or newer models)
  • Mac mini (Early 2009 or newer models)
  • Mac Pro (Early 2008 or newer models)
  • Xserve (Early 2009)

The requirements:
  • OS X 10.6.8 or later.
  • 2 GB of memory
  • 8 GB of available space
  • Some features require an Apple ID.
  • Some features require a compatible Internet package, subscription fees may apply.

Upgrading from a previous version

From OS X Snow Leopard:
  • If you have Snow Leopard( 10.6.x), install the latest version of OS X Snow Leopard before downloading Mavericks OS X on the Mac AppStore. Click the Apple icon and choose Software Update to install OS X Snow Leopard 10.6.8.

From OS X Leopard:

Some recommendations

To smoothly run OS X Mavericks:
  • Have at least 4 GB of RAM installed.
  • Have an existing iCloud account (Apple ID).
  • USB of 8 GB or an external drive.
    • First of all, go to Finder/Preferences/Sidebar/Devices.
    • Make sure that the boxes next to Hard Drives and External Hard Drives are checked.

STEP 1 - Download the Mavericks

  • Open App Store.
  • Sign-in using your Apple ID.
  • Click OS X Mavericks.
  • Click on the Download button.
  • Wait for the download to be completed (5.3 GB).

Once the download is completed:
  • The installation window automatically launches.
  • Do not click on "Continue".
  • From the menu bar, go to "Install OS X Mavericks / Exit OS X Mavericks installation"
  • Navigate to your Applications folder and locate the installation package named as "Install OS X Mavericks"
  • Copy the application to an external device.

STEP 2 - Prepare the installation USB

  • Insert your blank USB key into a USB port (not on the keyboard, but on the Mac itself).
  • Run Disk Utility located in Applications/Utilities...
  • On the left of the Disk Utility, select your USB drive.
  • On the right side of the window , click the "Partition" button.
  • In the "Partition Scheme" section you will see a button named as "Current".
  • Pull the "Current" button and choose " 1 Partition".
  • Click on the "Options ..." button.
  • Choose GUID and press the "OK" button.
  • Select the "Mac OS Extended (Journaled)" format.
  • Click on the "Apply" button at the bottom right .
  • Confirm and wait for the operation to be completed.

At this point the key is ready.
Now you will need to make hidden system files visible. This can be achieved using a small freeware: iTweaX.
  • Start iTweaX.
  • Click on the "Tweaks".
  • Check the "Show Hidden Files and Folders".
  • Click on the "Apply" button.

STEP 3 - Extraction of files

  • For more convenience, align the Finder and Disk Utility windows side by side.
  • Go to your "Applications" folder.
  • Right-click on the "Install OS X Mavericks" application and choose "Show Package Contents".
  • In the "Contents" folder, navigate to "SharedSupport" > "InstallESD.dmg".
  • Double-click on the disk image to mount it in Finder.
  • Wait for the integrity check to be performed.
  • Once mounted, you will noticed the presence of another image called as "BaseSystem.dmg" and a file named as "Packages" next to it.
  • Right-click it on "BaseSystem.dmg" and choose "Open".
  • Wait for the integrity check to be performed.
  • At this point we have two disk images mounted in the left column of the Finder:
    • OS X Install ESD
    • OS X Base System
  • In the left column of the Finder, drag the "OS X Base System" item at the top of the "Devices".
  • Return to the Disk Utility window.
  • Click on the "BaseSystem.dmg" line - it is now highlighted in blue.
  • Click on the "Restore" button in the right part of the window.
  • In "Destination", select the partition of the USB stick - not the physical key itself. This partition is by default named as "Untitled".
  • In the "Source" field you shall have "BaseSystem.dmg" and "Destination" area by the name of the partition of the USB drive.
  • Click on the "Restore" button in the bottom right of the window.
  • Confirm the request by clicking on the Delete button.
  • The system will ask for your administrator password.
  • Enter your password, click on OK and wait for the process to end.

Step 4 - Finalize the key

  • Go to the Finder
  • In the left column, eject the "OS X Base System" image, located at the top of the list.

You should have only two disk images mounted at this stage.
  • A disk image named OS X Install ESD, created out of the original installation package
  • A disk image named OS X Base System, representing the USB key.
  • Go back to your USB (OS X Base System)
  • Navigate to "System/System/Installation"
  • Discard the alias file named as "Packages" and empty the trash.
  • Go to the "InstallESD.dmg" disk image.
  • Select the "Packages" folder.
  • Press the CMD key + C to copy the files
  • Return to "OS X Base System/System/Installation"
  • Press the CMD key + C to paste the files

Once all these steps are completed, your USB drive is operational.
  • You can now eject the two disk images from the Finder again and hide system files via iTweaX .

Note that

There are 2 methods to start a fresh installation of MacOSX:
  • Boot the Mac from the USB key (connect the USB key and start your Mac while pressing the Alt key down).
  • Go to the menu bar and select the Disk Utility.

The two choices are available:
  • We simply delete/ format the standard working partition in Mac OS.
  • Create a new partition on the hard drive (GUID).

What's the difference?
  • In the first case, any existing backup partition will be preserved.
  • In the second case, Mavericks will be installed without any rescue partition.

Related :

This document entitled « Create an installation USB for OS X 10.9 (Mavericks) » from CCM ( is made available under the Creative Commons license. You can copy, modify copies of this page, under the conditions stipulated by the license, as this note appears clearly.