Carbon Copy Cloner

A useful backup approach is a bootable clone —an exact copy of your hard drive on another drive—which lets you get back up and running in no time should disaster strike. Unfortunately, thanks to permissions, invisible files, and other issues, you can’t just copy an OS X drive via drag and drop. What you need is a cloning utility that understands all of OS X’s peculiarities. Carbon Copy makes it easy to choose a source drive and a destination drive and then start the copy, and allows you to synchronize your clone with changes you made to the original.