Dear Lifehacker, I want to sync just my documents folder with an external drive, but I don't want documents removed from the backup drive in case I need to restore them. What should I do? Sincerely, NeedsBackup
Dear NeedsBackup, You can accomplish this in short order with the freeware version of SyncBack The key to doing a one-way backup is located in the profile setup screen, where you will first choose to backup everything under the directory:
And then on the advanced screen you'll find the important setting: make sure that "What to do if a file is in the destination but not in the source" is set to "Do nothing", which will leave your backup files alone even if they have been removed from your documents folder.
Love and Geekery,