Sorry if this has already been covered...couldn't find a similar problem in the forum.
My primary linux/ubuntu partition shows up twice (both instances display similarly) under the file system tab of gnome-system-monitor. Not sure if this has something to do with my fstab file (output below). I've also attached a gnome-system-monitor screenshot.
The GNOME developers announced a few days ago the immediate availability for download and testing of the fifth development release towards GNOME System Monitor 3.10, for the upcoming GNOME 3.10 desktop environment.