Starting with Xubuntu 14.10 (I think) I found that my favorite backup program, FreeFileSync, was not as easily installed via ppa as it had been in earlier versions. The getdeb repository contains this and many other programs but I had reason to wonder whether this would continue to be supported long-term. A few days ago I found grsync, a GTK-based interface to the venerable (but extremely powerful) rsync utility. Today, I put this to the true test: I needed to copy all of my user data from the exFat partition that I setup from my old Xubuntu Linux box to my completely newly formatted Xubuntu 15.04 box. See previous posts for details of the exFat fail. I copied about 800 GB of data during 1 session then copied the remaining 200 GB of data during another session. I first ran a simulation, though, as I was concerned about grsync’s ability to recover where it left off and not start from scratch or otherwise dump a bunch of data. Turns out, it scanned for several minutes but then happily continued from its previous location in the restore, with no fuss. I think I’ve found a new friend.
Of course, YMMV.