Hello, I would like to mirror selected folders on two external hard drives attached to my MacMini. I do not want to mirror the entire drive contents, just the selected folders. I periodically make changes to the contents of the folders on each respective drive, and then I will periodically plug-in both drives into my MacMini and would like the contents to synchronize across the selected folders. So to be clear, there is not a Master Drive in this case; drive 1 has the master folder for my photos, and drive 2 has the master folder for my music. I would like the changes I make to photos on drive 1 to sync to drive 2, and I would like the changes I make to music on drive 2 to sync to drive 1. Does that make sense? Suggestions? Thanks.