OS X's Disk Utility has a hidden Debug menu that, when enabled, can give you access to a few more Disk Utility features than you normally see. While Disk Utility has had a Debug menu for quite a while, it became even more useful with the advent of OS X Lion.
With OS X Lion, Apple added a restore partition on the startup drive that you can use to boot from and run utilities such as Disk Utility, re-install OS X, and even access the Internet to find solutions to problems you may be having. The restore partition is hidden, however, and isn't visible from within Disk Utility.
This can lead to a number of issues, including the possibility, over time, of having multiple restore partitions on various drives as you duplicate drives, replace drives, or re-install Lion. It can also prevent you from moving the restore partition to a new drive, should you ever need to replace a drive or just want to move things around on your drives.
It's understandable why Apple wants to hide some of the recovery partition. For instance, when you format a drive, the process creates a small 200 MB partition that the EFI bios needs for booting. These small EFI partitions don't contain any data that end users need, and there's no reason for them to be visible. But if you would like to be able to access the OS X Lion recovery partition to create clones or backups, enabling the Debug menu in Disk Utility is the easiest way to see and work with these invisible partitions.
Enable the Debug Menu in Disk Utility
- Quit Disk Utility if it is open.
- Launch Terminal, located at /Applications/Utilities.
- Enter the following command at the Terminal prompt:
- Press enter or return.
- Close Terminal.
defaults write com.apple.DiskUtility DUDebugMenuEnabled 1
The next time you launch Disk Utility, the Debug menu will be available.
If you wish to turn the Debug menu off again, perform the following steps.
Disable the Debug Menu in Disk Utility
- Quit Disk Utility if it is open.
- Launch Terminal, located at /Applications/Utilities.
- Enter the following command at the Terminal prompt:
- Press enter or return.
- Close Terminal.
defaults write com.apple.DiskUtility DUDebugMenuEnabled 0
That's all there is to enabling or disabling the Disk Utility Debug menu.
