Apple Seeds OS X Mavericks “Golden Master” Build. Here’s How To Create An OS X Mavericks Boot Disk.

Apple Seeds OS X Mavericks “Golden Master” Build. Here’s How To Create An OS X Mavericks Boot Disk.

Apple has this weekend seeded the “Golden Master” edtition of its upcoming operating system – OS X Mavericks – to developers of the ADC.

“Take advantage of new features, like APIs that optimize the new energy saving technologies in OS X Mavericks, as well as new AV Kit frameworks, Sprite Kit, Map Kit, and many powerful additions to existing frameworks. Download OS X Mavericks GM seed and Xcode 5.0.1 GM seed, now available on the Mac Dev Center.”

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For those unaware, when a piece of software reaches “Golden Master” status it is from then on considered “final.” In fact, (in most instances), this version of the software will often be identical to the version eventually released for public download.

While it is not yet clear when exactly Apple will choose to release OS X Mavericks for public download through the Mac App Store, all signs are currently pointing to a late October release.

Creating An OS X Mavericks Boot Disk

One of the most frustrating aspects of installing a new version of OS X is that Apple, (by default), unfortunately no longer gives the user the option to perform a “clean install” right out of the box. That is, an install which wipes the to-be-upgraded machine of all of its previously stored files, and software, in order to install a completely fresh copy of the upgraded software.

Thankfully, though, there is a way to get around this. It involves creating a “boot disk” — or, a temporary disk that will allow OS X to install, (and then boot), the desired operating system using an external drive.

However, there’s some things you should know:

[alert]Important: The steps listed below are provided for educational purposes only and require modifying disk states in order to install pre-release software. By following the guide you agree that you are proceeding at your own risk. RazorianFly (and its representatives) cannot be held responsible for any harm or damage caused to you as a person, or your equipment, as a result of you following the guide below.

Ready to get going?Okay, then!

What You’ll Need:

1. OS X Mavericks (Golden Master). This can be downloaded through the Mac App Store by all registered Mac developers, by taking advantage of the promo code Apple provides to you when you log-in at

2. A clean external hard drive (or pen drive) which is at least 8GB in unformatted disk space size.

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How To Create An OS X Mavericks Boot Disk

[alert]Note: The method below will install a fresh copy of OS X Mavericks GM onto your chosen Mac system. You should note that the process will overwrite all existing files. Please ensure you have backed up all your important data before you proceed.[/alert]

1. Open Terminal app and key in the following commands:

defaults write AppleShowAllFiles YES
killall Finder

This tells OS X to show you all ‘hidden files.’ You can undo this step later by typing the following commands:

defaults write AppleShowAllFiles NO
killall Finder

2. Obtain a copy of OS X Mavericks (Golden Master) from the Mac App Store, using the promo code provided by Apple on the Developer Console.

3. Locate the ‘Installer’ for OS X Mavericks (usually found in the ‘Applications’ folder, and named “Install OS X 10.9”).

4. Right click the OS X Mavericks ‘Installer’ file, (called “Install OS X 10.9”), and select the option “Show Package Contents.”

5. Locate the “Contents” folder and open it, then locate and open the folder called “Shared Support” (which is located within the “Contents” folder).

6. Double click “InstallESD.dmg” (which is located within the “Shared Support” folder). This will mount the install file in a new window. Now that we have successfully told OS X to show us hidden files (see ‘Step 1’), you should now see a file called “BaseSystem.dmg.”

[alert]Important: Leave this window open, as we’ll return to it later.[/alert]

7. Plugin your blank external hard drive, (or ‘pen drive’). Then, open “Disk Utility” app and select your external drive from the listed drives on the left. Ensuring that your external drive is still selected, head to the ‘Erase’ tab. Then click ‘Erase.’ (‘Mac OS Extended – Journaled’ from the ‘Format’ drop down should be selected while this is happening).

8. Once the disk has been reformatted, head to the ‘Restore’ tab (far right). Click and drag “BaseSystem.dmg” from the window we opened in the background earlier, to the ‘Source’ field on the ‘Restore’ tab (within “Disk Utility”).

9. Next, drag your external drive (or pen drive) listed on the left of Disk Utility to the ‘Destination’ field on the ‘Restore’ tab.

10. Click “Restore.”

11. Once complete, this will open a new window called “OS X Base System.” You’ll want to head to the folder “System” and then to the folder “Installation.” Here you’ll find an alias for “Packages.” We’re going to delete this alias (select the file, right click, “Move to Trash”).

12. Return to the InstallESD volume, (the one we clicked ‘Show Package Contents’ on earlier), and copy the full “Packages” folder. We’re going to replace the “Packages” folder we just deleted with this new “Packages” folder.

13. With your external drive, (or pen drive), still plugged-in, restart your Mac, and immediately hold down the Shift key. This will enter disk select mode. Wait for your external drive to show up as a bootable option, and click the ‘arrow’ below it. The disk should boot and enter the OS X Mavericks install setup.

14. Simply follow the on-screen steps from here to perform a “fresh install” of OS X Mavericks. Enjoy!

/ Marek Bell (h/t)