Just checking: does this key combo work? (Please respond.)

[Sergeant Pepper]

I'm planning on using Carbon Copy Cloner to create a bootable backup of my system and placing that backup on an external hard drive.

In case something goes wrong with my internal drive, will the key combo "Command + Option + Shift + Delete" (when pressed and held at startup) allow me to boot from my backup on the external drive?

 

[ihabime]

That will make it boot from the next available boot volume, whether it's the optical drive or external HD.

You can also just hold down the option key to get to a menu where you can choose the boot volume by hand.