How do I clone my drive to a external USB drive?
Before you can clone your hard drive with CarbonCopyCloner, you need to create a partition on the drive and format it appropriately for use with your Mac. Most external drives come pre-formatted for use with Windows machines.

You can use Disk Utility for this purpose. You'll find Disk Utility under /Applications/Utilities/Disk Utility on your machine.

In Disk Utility, look along the left hand bar for the USB-attached drive. If it has a partition on it already you'll see the drive listed, with the partition indented below the drive in the list:



Select the drive, not the partition, and then use the Erase tab on wipe the drive. You want to format the drive as Mac OS Extended (Journaled). You can give the drive a friendly name if you like. Once Disk Utility has wiped and formatted the drive with the appropriate file system you'll be able to use it as a clone target in CarbonCopyCloner: