As many others mentioned already "sync is not backup". If you really want true backup then on a Mac I will suggest to have a setup like: 1- local backup for qu

As many others mentioned already "sync is not backup". If you really want true backup then on a Mac I will suggest to have a setup like: 1- local backup for quick recovery with Time Machine 2- remote backup with a true backup solution like CrashPlan (or similar) I personally have such setup with a local one with my Time Machine, and having CrashPlan running all the time, it did save me a couple times when after many weeks I deleted a wrong file or folder... Got everything back without problem. If you don't have a Time Capsule, then you can always consider an alternative with just a smaller subset of what you want to archive by using a JetDrive by Transcend. I recently got a 128GB JetDrive and it is my local destination for my MBP for TimeMachine... Yes 128GB is not enough but knowing that CrashPlan is constantly running make me comfortable enough with that setup.