What is xfce4-mount-plugin?
The mount plugin allows you to mount devices such as hard disks,
CD/DVD-ROM and network filesystems listed in your /etc/fstab and to also
unmount currently mounted filesystems. You can specify custom commands
for the mount/unmount operations, eject CDs, run a command after a
device has been mounted (for example, exo-open to browse it in your file
manager), and finally you can quickly see how full a filesystem is, and
whether it's already mounted.