I was seeing a number of print_req_error: I/O error, fd0, sector 0 on an Ubuntu Server 18.04 virtual machine. It's running in Hyper-V, and there is no floppy configured in the Hypervisor.

There was nothing in /etc/fstab regarding fd0. After a bit of searching I found this procedure which resolved the issue.

$ echo "blacklist floppy" | sudo tee /etc/modprobe.d/blacklist-floppy.conf
$ sudo rmmod floppy
$ sudo update-initramfs -u
$ sudo shutdown -r now