libvirt network error - no 'default' network device found

list files in

/etc/libvirt/qemu/networks/

and

/etc/libvirt/qemu/networks/autostart/

if empty - create it

useful commands:

virsh net-start default

or

virsh net-autostart default

and

virsh net-destroy default
virsh net-undefine default
service libvirtd restart

for detailed explanation read wiki: http://wiki.libvirt.org/page/Networking

List available networks and specify the one you need:

virsh net-list

You can use virt-manager GUI too.

This is actually expected behaviour it seems .. something to do with how NAT forwarding is set-up by default. The system expects a 'default' network, bound to virbr0. So, if you delete that network, virt-install would no longer run as expected.

You probably can work around this if you are willing to poke around the innards of libvirt config files, and modify all relevant configuration file defaults. The error message can also be made more useful and explanatory ..

To recreate the network, first move off the network currently assigned to virbr0, and then:

# virsh net-define /usr/share/libvirt/networks/default.xml
Network default defined from /usr/share/libvirt/networks/default.xml
# virsh net-autostart default
Network default marked as autostarted
# virsh net-start default
Network default started`

Of course, you can also recreate the 'default' network via the virt-manager or other GUI ..

See more details here