One of my biggest concerns about Apple distributing Mac OS X 10.7 Lion via the Mac App store has been resolved. One intrepid Lion beta tester has discovered a hidden secret inside of Lion’s installation application.
Egg Freckles discovered that the Lion installer contains InstallESD.dmg a file that can be used to create bootable Lion installation media. This is great for all the experts in the audience who can really use a solution like this. Novices on the other hand might need some extra help.
Here are the steps:
- Purchase and download Lion from the Mac App Store on any Lion compatible Mac running Snow Leopard.
- Right click on “Mac OS X Lion” installer and choose the option to “Show Package Contents.”
- Inside the Contents folder that appears you will find a SharedSupport folder and inside the SharedSupport folder you will find the “InstallESD.dmg.” This is the Lion boot disc image we have all been waiting for.
- Copy “InstallESD.dmg” to another folder like the Desktop.
- Launch Disk Utility and click the burn button.
- Select the copied “InstallESD.dmg” as the image to burn, insert a standard sized 4.7 GB DVD, and wait for your new Lion Boot Disc to come out toasty hot.
Egg Freckles states:
With this disc you can boot any Lion compatible Mac, and install 10.7 just like you installed previous version of Mac OS X. You can even use Disk Utility’s Restore function to image your Lion boot disc image onto an external drive suitable for performing a clean install on a optical-drive-less MacBook Air, or Mac mini server.
I hope Apple will come up with a better more elegant solution for all users. For example, perhaps Apple will include a feature in the release version of Lion that creates a bootable CD/DVD or USB stick for emergencies.
This discovery is definitely one of the best ones about Lion that I’ve heard about yet. It saves the world of computer repair and data recovery for future Lion based systems. It also means we’ll have access to traditional troubleshooting tools that many of us are not ready to give up yet.
Updated 06/10/2011 at 6:30 AM PDT: Cult of Mac reader Martien comments that Mac OS X Lion still requires an internet connection to authenticate against Apple servers even when installed from a user-created CD/DVD or USB stick.