Unable to boot Fedora LiveCD from USB pendrive with qemu-system

[Marcin Zajączkowski]

Hi. Having some (dracut-related) issues with a Fedora LiveCD installed
on a pendrive, I wanted to play with it using qemu instead of a real
computer. Unfortunately, while the pendrive boot fine in real, with
qemu, I ended up with "Booting from Hard Drive..." displayed and 2
vCores working on 100% for several minutes (until I interrupted it).
Most likely, it is a problem with the way I try to achieve that:

> sudo qemu-system-x86_64 -enable-kvm -m 4196 -drive 
> file=/dev/sdb,format=raw,index=0,media=disk -boot menu=on

or more "dangerous" variant:
> sudo qemu-system-x86_64 -enable-kvm -m 4196 -hda /dev/sdb -boot menu=on


What could be wrong with that approach? What is the best way to boot a
VM using a bootable disk connected as a USB device (here recognized as
/dev/sdb)?


Marcin