Has this ever happened to you?
A few weeks back I copied a bunch of my music files in a folder on my Mac to a backup drive. Then I erased the files from my Mac – after all, I just backed them up. Weeks go by and I rip some more music. I then – thinking of how XP will ‘merge’ the contents of two folders with the same name in a copy operation – drag and drop the folder I put my music in (now with new music) over to my backup drive.
Unfortunately with Finder I quickly learned that such an operation is a replace of the previous folder that was copied. The result is that all of the contents that was there previously has been wiped out. Glad all of that material was on my iPod.
There are several utilities you can buy like Synchronize! X. But if you don’t mind using the Terminal app you can do this for free.
With your backup volume connected to your Mac the following will back up the currently selected directory to the volume you specify:
ditto -V . /Volumes/<DestinationVolume>/DestinationFolder
If you’re still looking for free utility SyncR might help. It’s a GUI front-end to the ditto command.