How to share a physical hard drive over the network using QEMU-NBD

Server setup

On the server (the computer with the physical hard drive), run

sudo qemu-nbd -p 10809 -f raw /dev/sda

Leave this running

Client

On the client, run

sudo nbd-client 10.1.2.3 10809 /dev/nbd0 

Run QEMU

Now you can run QEMU with the shared drive:

sudo qemu-system-x86_64 -smp 4 -enable-kvm -drive file=/dev/nbd0,format=raw -boot c -m 8G -net nic -net user