By default Ubuntu is configured to load the floppy kernel driver on start-up, if you don’t have a floppy drive though this can be annoying because the icon will appear as a un-mounted drive on your system. In Xubuntu on my machine the icon and entry in thunar (the file manager) looked like this.

The fix is to unload the floppy driver from memory, thankfully on Ubuntu its a module so you can unload the module with the following command:

sudo rmmod floppy

If you want to permanently stop it from loading on boot you can blacklist the driver as follows:

echo “blacklist floppy” | sudo tee /etc/modprobe.d/blacklist-floppy.conf
sudo rmmod floppy
sudo update-initramfs -u